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. WNacre tinged with salmon under the 
umbos, milky white anteriorly and of a bright blue and irridescent 
behind. Width, 24 in., length 14 in., diam. 2 in. 
Habitat.—Suwannee River, Suwannee County, Florida. 
Type in National Museum. 
Remarks.—This species seems to be related to both the amygdalum 
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. 
RECENT PUBLICATIONS. 
SyNopsis OF THE RECENT AND TERTIARY PSAMMOBIID OF 
Norro America, by W. H. Dall (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 Sanguinolaria 
Nuttallii Conrad as the type. Heterodonax has been removed from 
the family Donacide 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 thespecies are given. By the way, 
