340 PROCEEDINGS OF UNITED STATES NATIONAL MUSEUM. 
age and disproportionately thick ; in one specimen I found nearly fifty 
young ones, about 0.20™™ in diameter, lenticular, extremely thin, but 
alreatly showing the purple tinge, rather compressed and with hardly 
perceptible beaks, while the adult is inflated with very prominent 
beaks. The dimensions of a fully adult specimen are 3.0™ high, 2.25™™ 
in greatest length, and 2.5™™ in greatest thickness. They were ob- 
tained by Mr. Hemphill at Cedar Keys on mud flats, and at Sarasota 
Bay on the beach, abundantly. Conrad’s specimens came from Tampa 
Bay. The relations of this beautiful little shell are uncertain, but until 
more is known I should be disposed to keep it in the vicinity of Astarte, 
which, so far as the shell is concerned, appears to be its nearest relative, 
though I do not feel confident that this will be its permanent location. 
Crassatella (Hriphyla) lunulata Conrad. 
Beach of Sarasota Island, plenty but dead. 
There is little room for doubt that this name should take precedence 
over mactracea Linsley and that the two names refer to one and the 
same species. The specimens are the bright southern form of “ Gouldia” 
mactracea of authors. 
Cytherea (Transennella?) conradina un. s. 
Shell of much the same general form of C. cuneimeris Conrad, but with- 
out the radiating sculpture and the strong sculpture on the ribs. The 
color is nearly white with fine zigzag markings of yellow; a touch of 
pink internally in some valves; exterior smooth, or concentrically 
grooved; lunule marked by a strongly impressed line, proportionately 
large; escutcheon not distinguishable; shell moderately inflated, beaks 
not very prominent, recalling Oyrena floridana in shape but more rounded 
off; interior smooth, pallial sinus moderate, angular; beaks subcentral; 
margin internally grooved at right angles to the hypothetical radii of 
growth. Long, 8.0""; altitude, 5.7"; diameter, 5.0™. 
Habitat.—Rare at Cedar Keys, in mud between tides. 
The most remarkable feature of this shell is the internal grooving of 
the margins. The ventral margin is deeply scored parallel to the long 
axis of the shell, the grooves turning upward at the ends, while on each 
side of the beaks the margin is closely and,deeply grooved in a direction 
nearly parallel to the anterior and posterior slopes. I have seen nothing 
like itin any other bivalve. The grooves are not, as might be supposed, 
parallel with the lines of growth but invariably, except at the center of 
the base, form a more or less acute angle with them. The only analogue 
to such sculpture known to me occurs on the outside of such Lucinide as 
the Lamarekian L. divaricata, Woodia, and some Nuculid@ and Yoldias. 
But on the inside of any shell such sculpture has not, so far as I am 
aware, been reported, apart from structures appertaining to the hinge. 
Several gentlemen to whom the form in question has been submitted are 
unanimous in considering it as worthy of more than specific rank, and 
while I am yet in doubt as to the systematic value of the structure de- 
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