THE NAUTILUS. 137 
keeled, and cordate at the beaks. Cavity of the shell rather deep 
and uniform; cavity of the beaks well under the dorsum, blunt 
within. Cardinal teeth, low, compressed and double in both valves 
and nearly tubercular. Nacre white within the pallial line, and 
darker and iridescent exterior to it. Lateral teeth small, short, 
remote from the cardinals, and straight in the groove, but making a 
slight angle from the dorsal plate at the anterior end of the liga- 
ment, which is 3 of an inch long. Width i inches, length 14, di- 
ameter { of an inch. 
Habitat: Ocklocknee River, Leon Co., Fla. 
Remarks: Affinity, U. subangulatus Lea. Our shell differs from 
this in being more polished, thinner, rays broader, those of the an- 
terior end sweeping around in curves. The shell cavity is much 
deeper and broader. The beak cavities are much larger, and the 
shell substance white instead of incarnate. We take pleasure in 
naming this species, which is probably not exceeded in pictorial 
beauty by any known Unio in North America, in honor of Dr. 
Reynold J. Kirkland, of Grand Rapids, Michigan, who is a vigor- 
ous investigator in conchology. 
Unio Burtchianus sp. nov. 
Shell uniformly solid, though not thick, oblong-elliptical, flattish, 
inequilateral, smooth and polished, with a slight constriction near 
the middle. Sides rounded, anterior end rounded, pointed behind 
with a very short truncation. Dorsal and basal margins uniformly 
curved. Epidermis reddish, nearly oceulted with dark green rays 
running over all the surface, which are grouped in irregular fasci- 
cles, darker and densely striate on the posterior slope. Growth 
lines almost invisible. Beaks small and low, slightly rounded. 
Umbonal slope subangular, with a fainter ridge back of it, making 
a biangulation behind. Beak cavities very slight, confluent with a 
cavity under the lateral teeth. Shell cavity moderate and oblong. 
Cardinal teeth erect, light, crenulate, with an oblong groove in the 
cardinal of the right valve. The inner lateral tooth thickened and 
upturned at the end. Posterior cicatrices confluent, anterior dis- 
tinct, all well impressed. Pallial impression distinct and crenulate. 
Nacre salmon within the pallial line and purplish exterior to it. 
Width 2+ inches, length 14, diameter 8. 
Habitat: St. Mary’s River, Nassau Co., Florida. 
Remarks: Affinity, U. lehmanii, herein described, in which the 
distinction is made between these species. It is named in honor of 
