ACEPHALA. 389 
proportions are much more slender, or more like S. radiatus ; the 
hinge is fortified by a thickening along the dorsal margin. There is, 
indeed, the vestige of a rib from the beak towards the ventral margin, 
as in the shells above mentioned. 
Figures 502, 502 a, lateral and dorsal views of the shell; 5020, the 
hinge, with the interior. 
CyYPRICARDIA ROSEA (Gould). 
Testa transversa, oblonga, tenuis, antice radiatim tenut-striata, postice 
concentrice squamoso-striata: umbonibus valdé anticalibus, acutis ; 
latere antico brevi, citd angustato, ad apicem truncato, allido ; latere 
postico oblongo, ad apicem truncato, rosaceo ; margine dorsali viz ar- 
cuato ; margine ventral recto: intus rosacea: cardo debilis, dentibus 
Sere longitudinalibus. 
Cypricardia rosea, Goutp ; Proceed. Boston Soc. Nat. Hist., iii. 276. 
Expedition Shells, 84. 
SHELL thin, transversely oblong, more than twice as long as high, 
anterior extremity short, triangular, obtusely rounded at point; beaks 
at the anterior sixth of the length; posterior end square, upper 
and lower margins nearly parallel, a little arcuate above; umbonal 
region smooth and shining; posterior lamellate, its anterior two-thirds 
radiately and thickly striate ; colour dirty white, tinted rosaceous at the 
upper and posterior half; umbones moderately elevated, acute, touch- 
ing; hinge delicate, teeth almost longitudinal ; interior rosaceous. 
Length an inch and three-fourths; height three-fifths of an inch; 
width two-fifths of an inch. 
Inhabits the Feejee Islands. 
Allied to C. solenoides, Reeve, which is much more elongated, has 
purplish rays, and is only tinted purple posteriorly, within. C. corai- 
hophaga, Reeve, is somewhat more elongated, more laminated poste- 
riorly, and radiate striate, and the edge only is tinted rose-red within. 
98 
