THE NAUTILUS. 33 



thickened before. Ligament long, thin and reddish. Beaks prom- 

 inent and surrounded by coarse, oblique undulations, about four in 

 number and rather acute at summit. Epidermis fuscous, black and 

 deeply striate ; strong transmitted light shows a light-olive texture, 

 densely covered throughout with broad, greenish rays. Cardinal 

 teeth rather solid and deeply serrated. Lateral teeth long, slender, 

 straight, nearly smooth and extending to the posterior cardinal. 

 Posterior cicatrices scarcely visible ; anterior ones distinct. Beak 

 cavities slight and rounded. Nacre tinged with salmon under the 

 umbos, milky white anteriorly and of a bright blue and irridesceut 

 behind. Width, 2 in., length 11 in., diam. I in. 



Habitat. Suwannee River, Suwannee County, Florida. 



Type in National Museum. 



Remarks. This species seems to be related to both the ami/gdalum 

 and parvus groups, is readily distinguishable from any of its associates 

 by its remarkable width, beautiful rays and pointed, compressed 

 posterior. It reminds one most of U. minor Lea, with which it is 

 found, having the same dark, fuscous epidermis, and like that species 

 is disposed to be sub-truncate before, but the rays, light teeth, thinner 

 substance and greater size at once distinguish it. Some forms of U. 

 trossulus Lea approach it, but the beak sculpture, outline and teeth 

 are radically different, besides that species is never rough, but is 

 smooth, polished and yellowish when taken from the water; the 

 rays of the two species are quite similar, except that those of our 

 species are only visible by the aid of transmitted light. 



KECENT PUBLICATIONS. 



SYNOPSIS OF THE RECENT AND TERTIARY PSAMMOBIID.E OF 

 NORTH AMERICA, by W. H. Ball (Proc. Acad. Nat. Sciences of 

 Philadelphia, pages 57 to 62). The title of this paper gives some 

 idea of the ground covered by it. In the genus Psammobia a new 

 section Grammatomya, is made by Dr. Dall, and in the group 

 Sanguinolaria another one, Nuttallia is formed, with ftanguinolaria 

 Nuttallii Conrad as the type. Heterodonax has been removed from 

 the family Donacidre into this family. This will be gladly received 

 by collectors who have been sorely puzzled to find affinites in 

 Heterodonax bimaculata Lin. with Donax. Besides a full synonomy, 

 the geographical distribution of the species are given. By the way, 



