522 Capt. A. F. McArdle on 
There are one or two glands on the head, one at the anterior 
angle of, and the other behind, the orbit. 
Length 6-8 inches. Two specimens from the Bay of 
Bengal, 475 and 859-880 fath. 
This fish bears several points of resemblance to Gonostoma 
maderense (Johnson, Proc. Zool. Soc. 1890, p. 458), notably 
in the absence of fangs on the vomer and of an adipose dorsal 
fin; but in other respects it appears like a true Photichthys. 
It differs from G'. maderense in having scales on the back and 
none on the cheek, and in having but a single row of teeth 
in the anterior portion of the lower jaw. It is quite possible, 
too, that the small adipose fin may have got rubbed off in the 
‘ Investigator’ specimens. 
Named after Commander IT’. H. Heming, R.N., in gratitude 
for the interest and trouble he has invariably taken in the 
‘ Investigator’s’ zoological work, and the help he has given 
to the Surgeon-Naturalist. 
MACRURA. 
Family Thalassinide. 
CALASTACUS, Faxon. 
Calastacus longispinis, sp. n. 
Description of a female :—Carapace much shorter than 
abdomen, glabrous, laterally compressed, with the cervical 
groove well marked and with rounded antero-lateral angles. 
The rostrum is acutely triangular and short, about one-fourth 
the length of the remainder of the carapace. A slight but 
well-marked median carina runs backwards for about two- 
thirds of the way to the cervical groove, and carries a single 
blunt spine near its beginning. ‘The margins of the rostrum 
are spinous, having five teeth on either side in its free portion 
and two more on their continuation backwards as ridges over 
the carapace, where they extend as far as the level of the 
termination of the median carina, enclosing a horseshoe- 
shaped space. The gastric area supports three small spines 
on either side arranged in a longitudinal row, midway be- 
tween the median carina and the continuation of the rostral 
margins. 
Abdomen smooth and naked, the pleura of the first somite 
rudimentary and overlapped by those of the second, which, 
like those of the succeeding segments, are large and well 
developed. ‘The telson is quadrangular and broadly rounded 
off, as long as the swimmerets, and with a couple of minute 
