Various

“ The fall of the creek is considerable, being about 75 feet in two miles from Twenty-seventh Street to the Colorado, and this fall in connection with the shape of the bed gives to the current in times of flood a tremendous force.
During the first two years of this observation, 1912‒1913, the snail population of the creek in its middle stretches was dense. There were in particular two species very thickly represented, Planorbis lentus and Physa halei. So numerous were they that one could in a few moments within a very few feet gather a pint of either kind. ”

“ All this is perfectly true of this region. We were constantly amazed by the great number of specimens to be found; and each day of exploration in some new valley or over some range of hills added even greater figures of abundance to our already astonishing records.
The “prevailing” snail of this region is Cepolis ovumreguli Lea. Its shell is very suggestive of the true helix of Spain or Algeria of the lactea group. The variation is exceedingly great 43in color, size and shape, and it would make a dozen excellent species if the intermediates were left out of account. ”

“ The septate shell is oblong, the sides being nearly parallel, but slightly expanding anteriorly, the right slightly convex and the left slightly concave; the posterior margin is regularly rounded; the anterior more broadly rounded; the apex depressed, bluntly rounded, excentric, reaching nearly to the right margin, smooth except for slight concentric wrinkles, lines of growth fine and regular; the anterior slope is slightly convex; the very short posterior slope below the projecting apex to the line of the septum is straight and oblique ”

“ The chief facts of interest in regard to the habits of snails as shown by these observations, are these: 1, The snails of both species are to be found commonly in uncontaminated water which is running at a fairly rapid rate, and the most common orientation is with the heads pointing up stream; 2, The snail population in any stream is subject to wide fluctations depending upon flood conditions; 3, Physa because of its shape is less affected by floods than Planorbis ”

“ Under the name of Chama gigas the father of Natural History seems to have embraced the whole of the modern genus Tridacna. For the name gigas, as restricted to a single species, the candidates are the shell subsequently named squamosa by Lamarck and a huge species whose valves in the Ulrica Museum, together weighed 498 pounds. ”

“ The shell is typically more slender than A. lustrica, turrited-conic, narrowly umbilicate, corneous, minutely striate. The apex is slightly obtuse, but the first whorl projects visibly, as in lustrica, whorls very convex, parted by a deep suture. The aperture is ovate, small, its length contained more than 3 times in that of the shell; upper extremity narrowly rounded. The peristome is continuous, thin, very briefly in contact with the preceding whorl above. ”

“ The soft parts are those of the genus Fusconaia: the supraanal is separated from the anal by a very short mantle-connection, which is absent (or torn?) in rare cases. Inner lamina of inner gills free from abdominal sac. All four gills are marsupial. Placentae well developed and subcylindrical.
Branchial opening with well developed papillae, anal with distinct, but small papillae. Palpi subfalciform, posterior margins connected at base only.
While thus the Fusconaia structure is typically developed, this species is quite unique in its color. ”

“ These are very peculiar tints, by which this species is easily recognized in the field: four marsupial gills of this blackish-purple color are not known in any other Nayad.
Glochidia have been found only in specimens belonging to the headwaters variety (barnesiana bigbyensis) . They are subelliptical, slightly higher than long, L. 0.15, H. 0.16 mm.
Although a true Fusconaia, this species (or group of forms) stands isolated within the genus, in characters of the shell as well as in the soft parts. It differs from the species of the subrotunda-group (ind. ebena, pilaris etc.) ”

“ This activity stretches the girdle downward from the edges of the valves and permits a free play of all the valves so that the mantle deposits its shelly secretions according to the normal habit of the species. The specimens living in the pholad holes, however, apparently never leave them as they are frequently found feeding on the fucus which overhangs them. It protects them from the light, so they have no occasion to move about, and the sand which is washed down into these burrows would make re-entrance almost impossible. ”

“ Pfr., blue and yellow and buff in color. Another arboreal snail of this section is Polymita versicolor Born and it is probably very abundant in places although we never saw more than fifteen or twenty on any one tree. This is to me the least attractive species of that wonderful genus of richly painted snails. The brilliant yellow and pink are too primitive and the two colors do not seem to harmonize very well. It always impresses me as an experimental species that was laid aside in nature’s laboratory as not wholly a success. ”

“ The young specimens are very similar to young specimens from the tidepools, but as they increase in size they become crowded so that the valves press against each other, especially at the posterior end where the valves are bent back across the bottom of the hole. This crowding of the valves upon each other and the crowding of the girdle against the outer edges of the valves so displaces portions of the mantle as to cause the changes noted above. ”

“ Those living near the coast and among the cacti of the most arid parts of the district are of whiter and more dull color, are more banded and show a decided tendency to abnormalities, especially about the apertures. Specimens from further inland are more polished and shining, even as though varnished, and are much more given to a dotted or fly-specked type of ornamentation than to bands. ”

“ These conditions obtained especially in the early spring; as the breeding season, which in that latitude extends over half the year, passes by, the snails of course become much less numerous.
It is to be noted that previous to the time when the snails had become so abundant, there had been no heavy rains of sufficient importance to be recorded since 1908. Excessive rains occurred in May 1908, November and May 1907, June and March 1905, May and April 1904, July and February 1903, July and November 1902. There was a very severe flood in the creek in April 1900. ”

“ The new form is ovate, of about the size of the other species, which it resembles in sculpture and in the lamellae of the parietal wall and columella. The two palatal plicae are subequal, the upper emerging to the lip, the lower one also long, reaching to the inner edge of the peristome. There is a very small nodule on the base of the columella. In griqualandica the lower palatal plica is short and very deeply immersed and there is a distinct though small basal plica within the base, in front of the lower palatal plica. ”

“ The soft parts are often uniformly pale, whitish, but may shade to orange, and the orange is most prominent on foot, adductors, and mantle-margin; but the paler tints prevail, and often the orange is replaced by yellowish or brown. The gills 62are pale, but are generally suffused with blackish. The gonads are brown to red, mostly of a peculiar dull lavender color in the female, and the latter color, or purplish brown, is the prevailing color of the eggs and placentae. ”

“ It seems to be a natural law that arid or desert lands support but few species of snails, but that these few species exist in great numbers and that they take on a very considerable range of variation. ”

“ This genus has for its type the Unio plicatulus, Küster, a species identified by von Martens as belonging to the Lampsiline shells, as aztecorum. Mr. Simpson however believed it to be nearly allied to the persulcatus, a markedly Unioid shell. In this the writer follows Mr. Simpson.
The genus Nephronaias as constituted by Mr. Simpson embraces two quite distinct groups, divisible as follows.
Nephronaias (s. s.) embraces plicatulus, persulcatus, melleus, dysoni, ortmanni, ravistellus, etc. Ample material of these two latter species show that they are anatomically very closely allied to Elliptio. ”

“ His eminence as a zoologist and unceasing activity as an investigator of the South American fauna, had won for it an honorable place among scientific institutions. We understand that his successors are men without knowledge of the biological sciences. ”

“ Very solid, wide, ashen; inside whitish, the posterior valve with 10, central valve 2‒3, anterior valve 12 slits. Length 72, breadth 40, divergence 130°. Carpenteria, near Sta. Barbara, Cal. This is scarcely more than an individual variation. The mantle (girdle) is normal. The sculpture is worn away except at the edge. It has evidently lived in a very exposed situation.”
From this description and the figure which he gives of the valves it would seem that this is the same form as my specimens from the pholad holes. I fully agree with Dr. Pilsbry that it is hardly worthy of varietal rank. ”

“ Shell subovate, being much wider posteriorly, the anterior margin rather shortly rounded, the right margin nearly rectilinear, but somewhat diverging anteriorly, the left margin obliquely expanded and broadly rounded, anterior margin wider and much more curved than the posterior; apex very excentric, depressed and decidedly turned toward the right side, bluntly rounded, smooth except for a few concentric wrinkles; color a very pale corneous, nearly pure white; lines of growth rather strong and 52irregular ”

“ Only the three largest divisions are to be regarded as varieties, in the other forms the characters are merely individual, although specimens representing only 60one (or a few) of these “forms” often prevail at a given locality.
a1. Flat, compressed, dia. of shell less than 40 per cent of the length (var. bigbyensis) .
b1. No rays, or rays obscure, color of epidermis brown, dark. ”

“ In this situation they grow quite regularly, showing but slight variation in form. They are active fellows and evidently sensitive to light; for if the rocks to which they are clinging are turned over, they soon glide away, always taking the shortest route to the under side of the rock.
While cleaning a lot of this species taken at San Pedro last fall two specimens were noticed which differed so widely from the others that they might easily have been mistaken for another species. ”

“ The female of this species has been described by Dr. Ortmann (1912) . Actinonaias embraces, besides the type, medellinus, gundlachi, (accepting Simpson’s interpretation of this latter species) , and others.
Psoronaias, Crosse and Fischer (1893) . This group of remarkable shells, embracing crocodilarum, psoricus, semigranosus, etc., was provisionally treated by Simpson as a group of Elliptio, but their remarkable sculpturing, and the deep beak cavities of some of their species, led him to observe that it was possible that the group should, after all, be placed in Quadrula. ”

“ There were some ground snails too, but to secure living ones 44required much grubbing up of tufts of tall grass and shaking out their roots, like digging up miniature potatoes. These are the Annularia putris (Gundl.) ”

“ The relations of mollusks to fish in Oneida Lake. By Frank Collins Baker. Technical Publication No. 4, New York State College of Forestry at Syracuse University. Pp. 366. Syracuse, N. Y., 1916. We are informed that it may be obtained free by those interested in the study of Mollusca by applying to the dean of the college, Dr. Hugh P. Baker.
5. Pupa griqualandica M. and P., 1893; the specimens used being from Pretoria. ”

“ As has been pointed out, in the latter group, the color of eggs and placentae is remarkable: in all other forms of Fusconaia, this varies from white to bright red.
I introduce here another species, in order to show that the barnesiana-type is also represented outside of the Cumberland-Tennessee drainage, namely in the Ozarks.
Fusconaia ozarkensis (Call) 1887. F. ozarkensis Call, Pr. U. S. Mus. 10, ’87, p. 499, pl. 27. Tr. St. Louis Ac. 7, ’95, p. 33, pl. 18. Lampsilis ozarkensis Meek & Clark, Bur. Fisher. Doc. no. ”