OF NORTH AMERICA. 203 



Clessin (op. cit.) discusses the group of Lymncza truncatula, plac- 

 ing humilis, desidiosa (^obrussa) curia, cubensis, galbana, etc., in it. 

 He also places solida, pallida and traski in the same group, clearly 

 showing that he did not understand these species. 



The Liver-fluke (Fasciola hepatica) has been found parasitic on 

 Lymncea truncatula (Journ. Conch., Ill, p. 329, 1882). 



Galba doddsi Sp. Nov. Plate XXVII, figures 5-8. 



Limnaa truncatula COCKERELL, Journ. Conch., VI, p. 63, 1889; Nautilus, 

 III, p. 9, 1889 (part). 



Limncea humilis HENDERSON, Univ. Col. Studies, IV, p. 179, 1907 (part). 



SHELL: Elongated, turreted; color brownish horn; surface with 

 very heavy growth lines, giving the shell a rough aspect; whorls 5^2, 

 plano-convex, the body whorl slightly ventricose ; spire turreted, a trifle 

 longer than the aperture ; sutures impressed ; aperture ovate or roundly 

 ovate; inner lip reflexed to form a projecting shelf, which is not 

 tightly appressed to the parietal wall, but is erect and emargines the 

 umbilical chink, which is large and conspicuous. 



Length. Breadth. Aperture length. Breadth. 



9.00 4.50 4.25 2.50 mill. Type. 



8.00 4.00 3.75 2.25 " 



G.50 3.75 3.00 2.00 " 



6.50 3.50 3.00 2.00 " 



TYPES : The Chicago Academy of Sciences, four specimens. No. 

 23937. 



TYPE LOCALITY: Hot Sulphur Springs, Colorado. 



JAW : Not differing materially from that of cubensis. 



RADULA: (PI. VI, fig. N). Formula: 7i L\+!+f+HHHf+i+<Wr 

 (25-1-25) ; central tooth with long, spade-shaped cusp; lateral teeth 

 bicuspid, the mesocone very large, pointed, the ectocone smaller, promi- 

 nent, placed rather high up on the reflection; there are two sets of 

 intermediate teeth ; the fifth and sixth teeth are tricuspid, the entocone 

 arising on the lower part of the mesocone and being rather small; 

 the seventh and eighth teeth have the mesocone almost subequal, the 

 ectocone splitting into two teeth which become smaller; the marginal 

 teeth begin on the ninth tooth, the entocone splitting into two or three 

 small cusps. There are over seventy rows of teeth. The radula of 

 doddsi is very uniform, exhibiting little or no variation among the 

 individual teeth. In one ribbon 26-1-26 were counted. 



GENITALIA : Resembling closely those of Galba cubensis. 



Male organs : The penis-sac is twice the length of the penis, which 

 is short and rather thick; the vas deferens is six times the length of 

 the penis; the prostate is large, oblong-ovate, contracted at the proxi- 



