16 



VIVIPARA. 



Fig. 22. 



Paludina nngu- 

 lata. 



This superb Paludina, wliicli far surpasses in point of beauty any of our 

 species yet known, I owe to the kindness of Judge Tait. Its beavitiful 

 double tuberculated cincture at once distinguishes it from all described 

 species. Some specimens are furnished with dark purple bands which 

 beautifully decorate the interior of the shell, and give a dark rich green 

 color to its fine epidermis. In the others these are wanting, and the epi- 

 dermis then has a clear and more yellow appearance. The sutures being 

 formed immediately over the lower row of tubercles, they cause its line to 

 be very irregular ; and this row itself is hidden on the upper whirls, (iea.) 



Paludina angulata, Lea — Shell inflated, thin, brown, above somewhat 

 varicose, below transversely and minutely striate, minutely perforate ; 

 spire rather short, dark at the apex ; sutures impressed ; 

 whirls five, angular in the middle ; aperture large, sub- 

 triangular, within subrubiginous. 



Coosa River, Alabama. Dr. Brumby. My cabinet, and 

 cabinets of Dr. Griffith, Dr. Jay, Dr. Foreman, T. G. Lea, 

 and J. Clark. Diam. .80, length 1.05 inch. 



This is a very distinct species, being more angular than 

 any I have seen. In the specimen before me, there are 

 three irregular transverse impressions, two above the an- 

 gle, and one immediately below. The strise are more dis- 

 tinct on the lower half of the whirl. The first three whirls are very dark. 

 The aperture is nearly one-half the length of the shell, and quite angular 

 at the base. 



Since the above was written, I have received more mature and perfect 

 specimens. They difi'er from the one described in being darker in the epi- 

 dermis, and in having four purple broad bands, which are very distinct 

 within the aperture. In these specimens, there is a series of indistinct 

 tubercles above the periphery of the last whirl. (Zea.) 



§ 2. Shell carinated. 



ViTipara miilticariiiata, Hald.— Shell conic, thin, subdiapha- 

 nous, green, whirls 5, longitudinally striate and transversely carinate. 



This Paludina is thinner and lighter than our spe- 

 cies, and has but 5 whirls. The length is about one- 

 fifth more than that of the last whirl, of which the 

 diameter is about double that of the penultimate 

 whirl ; beside the longitudinal strise, there are four 

 carinas, of which the first and third are stronger than 

 the second and fourth, and which cover the whole 

 length of each of the whirls. 



The opening is almost circular, yet the vertical is 

 greater than the transverse diameter. The lip is 

 slightly thickened, not acute ; the columella, which 

 is hardly distinct from the lip, joins the superior ter- 

 mination of the aperture under a slightly acute angle. 



Fig. 23. 



Paludina carinata. 



