14 LAND AND FRESII-WATER SHELLS OF N. A. [PAUT UI. 



which characters the last two seem to arise from the loose manner in which 

 the whirls are united. {Gould.) 



Valvata pupoidea, Gould, Am. Journ. So. 1st ser. XXXVIII, p. 196, 1840; 

 Invert, of Mass. p. 226, f. 155; Otia, ISO.— Haldeman, Mon. p. 10, 

 pi. i, fig. 11-13.— DeKay, N. Y. Moll. 119.— Chenu, Man. de Conch. 

 II, 311, fig. 2230.— Anonymous, Can. Nat. II, 214, fig. 



Fig. 19 is an enlarged view of one of Dr. Gould's figures. 

 Found also in Connecticut (Linsleij), District of Columbia (Gi- 

 rard), Maine (3Iighels), and Canada {Ca7i. Nat. i. c). 



This species is made the type of a new genus Lyogyrus, by Mr. 

 Gill. (Proc. Ac. Nat. Sci. Phil. 1863.) It does not appear to 

 me that there are sufficient grounds for believ^ing it distinct. 



Talvata liuiueralis, Say. — Shell subglohose, depressed ; spire con . 

 vex, not prominent; whirls three and a half, with the shoulder depressed, 

 plane ; wrinkled across, or rather with slightly raised lines ; aperture ap- 

 pressed to the penultimate whirl, but not interrupted by it ; umbilicus 

 rather large. Greatest breadth, less than one-fifth of an inch. 



Inhabits Mexico. 



DiS'ers from V. sincera, nob. of the Northwest Territory, in being more 

 depressed, and in having a shoulder or plain surface near the suture. The 

 umbilicus is larger than that of the V. piscinalis, Miill., and the spire more 

 depressed ; that species is also destitute of the depressed shoulder. (Say.} 



Valvata humeralis, Say, New Harm. Diss. II, 244 ; Descr. 22. Binney's 

 ed. p. 148. — Haldeman, Mon. p. 9. — Menke, Zeit. fiir Mai. II, 129. 



This Mexican species, not noticed since Mr. Say found it in 

 Mexico, has been quoted from Canada by Bell, Whiteaves, &c. 

 They probably refer to a variety of V. tricarinata. Compare 

 V. virens. 



Valvata Virens, Tkyon. — Shell turbiniform, consisting of four well 



rounded whirls ; spire elevated, apex acute, sutures deeply indented ; 



periphery almost angulated ; umbilicus very wide ; aper- 



Fig. 20. ture oval or nearly round, the peristome merely touching 



/"!2:-s r~^^ ^^^® body above. Surface closely striate. Color varying 



kj^ V37 from brilliant to dark-green. Height .5 ; diam. maj. .5, 



Valmtamrena. min. .4; of aperture, length 2.5, breadth 2 mill. 



