MUSEUM OF COMPARATIVE ZOOLOGY. 203 
teeth the rostrum tapers regularly to the point. The upper surface is plane 
and smooth. A slight median carina, most obvious near the tip, runs through 
the whole length of the rostrum from the anterior end of the gastric area to the 
tip; the lateral margins are slightly rimmed. The lower surface of the ros- 
trum is longitudinally grooved, and wholly devoid of a median keel. 
Orbital spine rather short and thick, directed a little outward and upward. 
The spine at the antero-external angle of the carapace is also short and thick, 
slightly exceeding in length the orbital spine. From its base a low keel ex- 
tends backward over the hepatic area,—a keel unarmed with spines, but 
broken into two tubercles, the hinder of which is the more prominent. In the 
small triangular area between this keel and the gastro-hepatic sulcus are several 
tubercles disposed for the most part in a single row. The gastric region is 
free from tubercles in the median line save one minute one at the anterior 
boundary near the base of the rostrum; but on either side, this region is orna- 
mented with tubercles ; these are not spiny, nor do they tend to form very well 
marked caring. On the branchial regions there are three carine on each side; 
the uppermost of these is broken up into five or six tubercles ; the top of these 
tubercles, as well as those of the other carine on the branchial and hepatic areas, 
exhibit a corroded surface, and a similar appearance is manifest on the whole 
lower surface of the carapace where it is bent beneath the thorax. The abdo- 
men is irregularly bestrewn with low tubercles. The telson is straight and 
much shorter than the rostrum ; it is furnished with a small, laterally com- 
pressed tooth in the median dorsal line at base; both the dorsal carin: and the 
lateral margins are obsoletely dentate along their basal half. 
Length, 124 mm. ; length of rostrum from tip to anterior gastric groove, 
30.5 mm. ; length of carapace, including rostrum, 58 mm. 
Station 3382. 1793 fathoms, 2 specimens. 
Family PANDALIDA. 
Heterocarpus vicarius, sp. nov. 
This is the Western representative of Æ. gibbosus Bate, from the Philippine 
Islands. It differs from that species as follows. The carapace is very much 
longer both in proportion to its height and to the length of the rostrum, and its 
dorsal margin is not so convex. The teeth on the upper edge of the rostrum 
are more numerous and closely set. The lateral carinw of the carapace are 
more prominent. The third abdominal somite forms a sharper angle or knee, 
Finally, the antennulary flagella are longer and subequal in length. 
Length, 110 mm. ; rostrum, 26 mm.; carapace, including rostrum, 55 mm. 
Station 3385. 286 fathoms. 49 specimens. 
d 3386. 242 “ 91 P 
di 9889, 210 T f 
d 3396, 259 “ 68 ii 
