100 
namely, at Russian Bodegas, San Francisco, and Santa Barbara, in 
from six to ten fathoms. 
Cab. Belcher. 
More ventricose and acutely beaked than N. pella, and presenting 
a partial obliteration of the sulci near the anterior dorsal margin. 
Nucuxa ventricosa. Nuc. testd oblonga, pallidé luted, ventricosé, 
sulcatd ; antice subrecté rostratd, umbonibus magnis, prominenti- 
bus ; margine ventrali antice coarctatd. Long. 7; lat. 34; alt. 
5 lin. y 
Hab. Straits of Malacca; from seventeen fathoms, mud. 
Cab. Belcher. 
The character of the sulcation here is very different to that of the 
preceding species and of N. pella. Here it presents the most usual 
features of regular furrows with intervening ridges ; but in the other 
two species the ridges are inclined planes, having an inclination 
towards the ventral margin. In this direction they consequently 
present a number of step-like elevations, but not in the contrary. 
Nucuxa recta. Nuc. testd oblongd, tumidd, inclinate sulcatd, rect 
et attenuate rostratd, postice rotundatd. Long. 6; lat. 24; alt. 
4 lin. 
Hab. New Guinea; in seven fathoms. 
Cab. Belcher et Cuming. 
Nucuta excavata. Nuc. testd globosd, sulcatd, gibbosé rostratd, 
antice carinatd ; lunuld excavatd, ovali, striatd. Long. 4; lat. 24; 
alt. 33 lin. 
Hab. Panama; dredged among mud in thirty fathoms. 
Cab. Belcher. 
Nucoura reticuntata. Nuc. testd parvd, oblongd, sulcatd, striis 
longitudinalibus interstitialibus reticulatd ; antice arcuate rostratd. 
Long. 3; lat. 14; alt. 2 lin. 
Hab. Philippine Islands, in several localities: namely, Cagayan, 
island of Misamis, from twenty-five fathoms ; Mindanao, from twenty- 
five fathoms, sandy mud; and Loay, island of Bobol, from sixty 
fathoms, clayey sand. 
Cab. Cuming. 
Nucura tyrata. Nuc. testd oblongd, nitidd, angulaté sulcatd, 
acute subrect? rostratd, postice elongatd, rotundatd ; margine ven- 
trali acuto integro. Long. 94; lat. 4; alt. 5 lin. 
Hab. Panama; from thirty fathoms. 
Cab. Belcher. 
Nucuza purtiata. Nuc. testd oblongd, nitidd, leviter striatd, an- 
tice breviter arcuate rostratd, postice rotundatd ; prope umbones 
turgidd. Long. 3; lat. 13; alt. 2 lin. 
Hab. Malacca; from ten to seventeen fathoms, coarse sand. 
Cab. Cuming et Belcher. 
Nucuna crispa. Nuc. testd oblongd, turgidd, sulcatd, arcuate ros- 
