38 



RANDOM NOTES ON NATURAL HISTORY. 



The Shell-Bearing Mollusca of Rhode 

 Island. 



BY HORACE F. CARPENTER. 



Chapter XXVIII. 



90. Patula. (Pseudohyalina) Minuscdla, 



BiNNEY. 



Syns. : 



Helix minuscula, Binn., Ad., Reeve, 

 Chetn., Morse. 



" minutalis, Morelet. 



" apex, Ad., Reeve. 



" lavelleana, D'Oi'b. 



'' mauriniana, " 

 Pseudohyalina, ininnscula, Tiyon, Morse. 

 Shell depressed-convex ; epidermis whitish; 

 whorls four, convex, not increasing rapidl}^ 

 in diameter, with microscopic wrinkles ; sut- 

 ure distinct ; lip simple ; aperture circular ; 

 umbilicus large and deep, showing the volu- 

 tions. Diameter one-tenth of an inch, 

 height one twenty-fifth. 



It inhabits from the Red River of the 

 North to Texas and Florida, in all the 

 states east of the Rockj- Mountains. It 

 has been quoted from California, Bermuda, 

 Cuba, Jamaica, and Porto Rico. I have col- 

 lected all the land shells of Bermuda, but 

 never saw this species there, and do not be- 

 lieve that it exists in any of the islands 

 mentioned. It is not at all common in 

 Rhode Island, but is found in great quanti- 

 ties in the West. In Cincinnati it is very 

 common in the grass and in gardens. It 

 was described bv Binney in Jour. Bost. Soc. 

 Nat. Hist., III., 453, 1840. 



Genus Vallonia Risso, 1826. 



Shell depressed, diaphanous, umbilicated, 

 whorls three and a half to four ; aperture 

 oblique, sub-circular; outer lip white, thick- 

 ened, reflected. There are but three or four 

 species, all minute, and are distributed all 

 over the northern portions of Europe, Asia, 

 and America. 



This genus has received other names, as 

 follows : Amplexus, Brown, 1827 ; Chil- 

 ostoraa, Fitz., 1833 ; Circinaria, Beck., 

 1837; Corneola, Held., 1837 ; Glaphyra, 

 Albers., 1850; Lucena, Moq-Tan., 1855, 

 etc. 



I 91. Vallonia Minuta, Say. 



S>/Hs. : 



Helix pulchella, Miill., Pfr., Binn,, Ad. 

 Gld., etc. 

 " costata, var., Miill. 

 " minuta, Say, Binn., DeKay, 

 Morse. 



Vallonia minuta, Morse, Tr3-ou, and 

 others. 



It is difficult to say whether the specific 

 name of this shell should be minuta or pul- 

 chella. If the American shell is identical 

 with the European species, pulchella has 

 the precedence, as Miiller named it in 1774 

 and Say in 1817. It does not seem possi- 

 ble that it could have been accidently intro- 

 duced from Europe, and spread all over the 

 United States in so short a time as this 

 countr}' has been known to commerce, and 

 it seems equally improbable that the same 

 species should have been created in both 

 hemispheres, with a wide ocean between on 

 botii sides. It is a fact that the shells from 

 both countries look preciseh' alike, but as 

 Professor Morse has examined the tongues of 

 many specimens of both species, and alwa3's 

 finds a diflTerence in the lingual dentition, 

 and as it is probable that other differences 

 may be observed in them, I prefer to call 

 our American shell by Say's name. It is 

 found under stones, on old walls, in gar- 

 dens and in grass growing on the banks of 

 rivers. I find it in Rhode Island more com- 

 monly on the under side of boards and rails 

 in damp places than in any other situation. 

 Dr. Perkins says it is common about the roots 

 of elms on the college grounds at Yale. 

 They are gregarious in their habits. I found 

 once, about twenty clustered together under 

 an old log and as many more on a board l3'ing 

 in the grass at Lime Rock, in Smithfield. In 

 both instances the localit\' was very damp 

 and must be under water a good portion of 

 the 3'ear. 



The shell is one-tenth of an inch in diam- 

 eter, white or nearl}' colorless, translucent, 

 with four whorls, the last spreading at the 

 aperture like a trumpet ; the lip is white, 

 thick, and reflected ; umbilicus large, show- 

 ing the volutions. A strongh' ribbed vari- 

 ety has been found in Kansas, at Cincinnati, 

 Philadelphia, and other places. I have 

 never seen any of this variety in Rhode Is- 

 land, and have none in mj^ collection, and 

 should be pleased to receive sj^ecimens 



