THE NAUTILUS. 129 



to size, shape, relative size and prominence of the beaks, stria? and 

 appearance of the surface, color, transluceiicy or opacity of the 

 shell. Some of the full-grown examples are straw-colored all over, 

 others horn or grayish with a broad or narrow light zone along the 

 margins. None of the different forms can be regarded and described 

 as typical and the others as varietal since they are connected by in- 

 tergradations. In younger specimens, the superior marjiin is '^ener- 

 ally less curved, the anterior and posterior more so than in the adult. 

 The rugosity of the inner surface of the shell is like that of Pis. nov- 

 eboraceiise, although microscopical, much coarser than e. g. in P. 

 variabile Pr. and compressum Pr. 



Pis. atlanticum seems nearest related to P. noveboraceiue, but the 

 mussel is shorter, its posterior part comparatively higher, the suppro- 

 anterior slope is steeper and the color is different. 



SOME NOTES ON BERMUDIAN MOLLUSKS. 



BY OAVEN BRYANT. 



Dr. Pilsbry, in his article on " The Air-breathing Mollusks of the 

 Bermudas" in Transactions of the Connecticut Academy (Vol. X 

 part 2, p. 493, Sept., 1900) says: "From the data supplied by Prof.' 

 VerriU's expedition and that of Prof. Heilprin, it seems that Val- 

 lonia pulchella, Cecilioides acicula, Agriolimax Icevis and Physa acuta 

 rest upon siilgle records now nearly twenty years old, and they may 

 not have permanently colonized; but as none of them are conspicu- 

 ous forms, and no special collectors of land shells have sought for 

 them, the merely negative evidence is inconclusive." 



In this connection it is interesting to note that Physa acuta Drap., 

 was found by Mr. Davis and recorded in the Nautilus (Vol. 

 XVII, p. 125, Mar., 1904). Cecilioides acicula Miill. and Vol- 

 lania pulchella Miill. were found by Mr. Addison Gulick and myself 

 on the grounds of the Hotel Frascati, while studying at the Ber- 

 muda Biological Station in July and August, 1903. A careful 

 search would very likely reveal Agriolimax laevis Miill. 



Vallonia pulchella (Miill.). 

 First recorded by Jones, 1876. (The Visitor's Guide to Ber- 



