VIVIPARA. 



29 



Paltuiino, svbsolida. 



Illinois. My cabinet ; cabinet of Hugh Fig. 48. 



Cuming, London. 



This is the most ponderous species in the 

 genus, far exceeding P. ponderosa, Say, in 

 tliat respect ; compared with that species it 

 is not only much more solid and heavy, but 

 its spire is proportionally more elongate, 

 whirls more convex, while the body whirl is 

 less ventricose, and the aperture is uncom- 

 monly small for a Paludina of its size ; the 

 body whirl is disposed to be angulated near 

 its middle; all the whirls are more or less 

 shouldered and the lines of growth are very 

 conspicuous ; the body whirl is obscurely 

 striate concentrically, and its surface thereby 

 modified so as to present a faintly sculptured 

 appearance, and the striae being somewhat 



finely undulated the appearance under a microscope is very pleasing. 

 (^Anthony.) 



Paludina keros, DeKay, of one of the earlier Zoological Re- 

 ports of New York; is said by that author to be a large form of 

 Pal. Integra. (N. Y. Moll. p. 85.) 



Of the forms generally known as Pal. decisa and integra I 

 have received specimens from Maine, lat. 47° (Morse), vicinity 

 of Montreal (Mrs. T. P. Girdwood), Ohio, Illinois, Michigan, 

 Iowa, Wisconsin, Kansas, Missouri, Mississippi, Tennessee, Tex- 

 as, Alabama, Georgia, South Carolina, North Carolina, Yirginia, 

 Maryland, Pennsylvania, New Jersey, New York, and all the 

 New England States. It appears a widely distributed species, 

 and may be said to inhabit the whole continent, east of the Rocky 

 Mountains and Rio Grande, to the boreal regions. 



Since writing the above, I have received from Mr. E. S. Morse, 

 of Portland, Me., drawings of the lingual membrane of the form 

 known as Viv. integra, received from Dr. J. Lewis, of Mohawk, 

 N. Y. I give below the drawing and Mr. Morse's notes. 



" Vivipara-integra. — Lingual membrane 

 composed of forty-eight rows of teeth, ar- 

 ranged in the form common to the group 

 3, 1, 3. Central tooth broad, short, and 

 hooked, a small shoulder each side near its 

 base ; first lateral broad and hooked ; second 

 and third lateral-long, claw-shaped ; anterior 

 part of membrane broad, narrowing toward 



Fig. 49. 



Lingual dentition of Vivipara 

 integra. 



