OF NORTH AMERICA. 217 



shell is also narrower and the upper whorls are rounder and more 

 turban-shaped. There is considerable variation in the form of the 

 shell of techella, the last whorl being either simply convex or 

 disproportionately swollen. The inner lip varies greatly in the extent 

 to which it is expanded or compressed. The spire also varies in height, 

 as do the sutures in their degree of impression. Some specimens some- 

 what closely resemble var. cockerelli, in which, however, the spire is 

 always very short. There is also great variation in size, individuals 

 from some localities being about half the size of those from other 

 localities. 



Old specimens have the last whorl distinctly malleated, but this 

 character is not apparent on shells of younger growth, which are 

 smooth and polished, with a comparatively short spire. The type lot 

 have the majority of the specimens with the spire eroded, for which 

 reason and on account of the insufficient figures of both Haldeman 

 and Tryon, the species has been misunderstood by most conchologists 

 and has been confounded with both bulimoidcs and cubensis. Dr. 

 Pilsbry (loc. cit.) was the first conchologist to correctly describe and 

 figure this form, which is one of the neatest of the American Lymngeas. 



Techella and cockerelli were once thought to be specifically sepa- 

 rable from bulimoidcs, but the examination of a large series of both 

 forms has proven conclusively that techella is but a race of bulimoides. 

 Techella, while normally possessing a broadly dilated inner lip, is some- 

 times seen with a folded inner lip as in bulimoides, but with the sharp 

 spire and obese body whorl of techella. Again, the inner lip may be 

 broadly expanded and the body whorl may be compressed as in buli- 

 moides. The latter also exhibits parallel cases of variation. 



Galba bulimoides cockerelli (Pilsbry and Ferriss). Plate XXVI, 

 figures 5-7 ; plate XXVIII, figures 4-7. 



Lymncea bulimoides cockerelli PILSBRY, Nautilus, XIX, p. 30, March, 1906. 

 PILSBRY and FERRISS, Proc. Phil. Acad., p. 162, figs. 13-17, 1906. HENDERSON, 

 Univ. Col. Stud., IV, pp. 93, 180, 1809. WALKER, Nautilus, XX, p. 108, 1907. 

 PILSBRY and FERRISS, Nautilus, XXII, p. 104, 1909; Proc. Phil. Acad., p. 144, 1910. 



Limnaa bulimoides BLAND and COOPER, Ann. N. Y. Lye. N. H., VII, p. 370, 

 1862. BINNEY, L. and F. W. Sh. N. A., II, p. 61, fig. 96, 1865 (nee. desc.). 

 STEARNS, N. Am. Fauna, VIII, p. 275, 1893. SQUYER, Nautilus, VIII, p. 65, 

 1894. PILSBRY, Nautilus, X, p. 96, 1896. STEARNS, Proc. Nat. Mus., XXIV, p. 

 288, 1901. ELROD, Bull. Univ. Mont., Biol. Ser., No. 3, p. 172, 1902. 



Lymn&a (Stagnicola) bulimoidcs DALL, Alaska Moll., fig. 62, 1906. HEN- 

 DERSON, Univ. Col. Studies, IV, p. 179, fig. 36, 1907. 



Lymncea bulimoides BERRY, Nautilus, XXIII, p. 77, 1909. 



Limnophysa bulimoides CALL, Bull. Wash. Lab. N. H., I, p. 118, 1885. 1 



1 From Call's description and his reference to Binney's figure 86, there 

 would seem to be little question that his specimens were cockerelli. 



