ACEPHALA. 405 
TELLINA TITHONIA (Gould). 
Testa transversa, oblonga, subequilateralis, zonis et radiis diversis albis 
et roseis picta, concentrice lirata, liris posticé lamellosis ; latere antico 
semiovali ; latere postico breviort, triangulari, ad apicem truncato ; 
plica profunda ; margine dorsal recto, dechvt: interior incarnata, ad 
marginem roseo-maculata, versus apicem lutea; dentibus lateralibus 
satis conspicuis. 
Tellina tithonia, Goutp; Proceed. Boston Soc. Nat. Hist., iii. 252. 
June 1850. Expedition Shells, 79. 
- SHELL twice as long as broad, beaks somewhat behind the middle; 
anterior half semi-elliptical, rounded at the extremity, superior edge 
rectilinear, basal edge very slightly curved; posterior end triangular, 
much curved to the right; superior edge straight, declivous, extremity 
truncated ; fold very decided; surface everywhere sculptured with 
deep, close, parallel, equal, simple grooves and ridges, which become 
lamellar as they pass the fold; colour milk-white, zoned and rayed 
with roseate; within deep flesh-coloured, cream-coloured toward the 
beaks; margin pencilled with the termination of the external red 
rays ; lateral teeth well developed. 
Length an inch and three-fourths; height seven-eighths of an inch. 
Inhabits the Sooloo Sea. 
Intermediate between J’ rastellum and T. pulchella, being smaller 
and of the same shape as the former, but without its peculiar squa- 
mous sculpture of the right valve; and being larger and more roseate 
than the latter, and from a very different locality. It is coloured like 
T. virgata, externally, but is more slender, and deeply coloured 
within also. It has the form and sculpture of T. maculata. 
Figure 518, lateral view of the shell ; 518 @, interior, with the hinge: 
518 b, dorsal view of the shell. 
102 
