204 Mr. A. Alcock on the Bathyhial Fishes 
same standard; its surface is studded with pores, those on the 
crown being elliptical and arranged in numerous longitudinal 
rows. Snout depressed, tapering, and rounded, its length 
being twice the diameter of the eye and one fourth the length 
of the head ; the lower jaw projects slightly. Eyes lateral, 
small, circular, deep-set; interorbital space twice the diameter 
of the eye and nearly flat from side to side ; it is traversed 
by two anteriorly-converging ridges which enclose a Y-shaped 
groove, in the centre and also at the apex of which is a lumi- 
nous (?) gland. Nostrils large, superior, situated near the tip 
of the snout. Cleft of mouth oblique, extremely wide, its 
angle nearly reaching the preopercular angle ; the maxilla, 
which is much more slender than the premaxilla, is almost 
three fourths the length of the head ; the symphyseal con- 
nexions are loose ; the labial folds are thin and almost obso- 
lete. Depressible hinged fangs in two rows, those of the inner 
row being much the larger, in both jaws, and a row of distant, 
fixed, recurved teeth in each palatine ; the most anterior and 
externa] premaxillary tooth is very stout, curved, and fixed. 
Tongue free, thin, foliate. Gill-openings wide ; gill-covers 
thin and flexible, the preoperculum with a very oblique edge, 
a small, stout, obliquely decurrent spine at its angle, and a 
thick muscular covering ; gill-membranes attached to the 
isthmus in its anterior half ; four gills, the last gill-cleft a 
small foramen, branchial arches extremely weak and flexible ; 
no gill-rakers ; pseudobranchias well developed. 
fckin entirely scaleless, thin, covered with a uniformly thick 
adherent layer of mucus; a single lateral line, which follows 
the dorsal profile from occiput to base of caudal. 
Two dorsal fins, separated by an interval equal to two 
thirds the length of the snout : the first, which begins slightly 
in advance of the vertical through the base of the pectoral, 
consists of ten slender but well-ossified spines, of which the 
longest (third) is barely as long as the rostro-orbital portion 
of the head ; the second contains twenty-nine slender articu- 
lated rays, branched at the tip and decreasing regularly in 
length from before backwards, the longest (second) being 
about half the length of the head. Anal equal, opposite and 
similar to the second dorsal. Caudal symmetrically forked. 
Pectorals slender, as long as the postorbital portion of the 
head, all the rays branched. Ventrals thoracic, equal in length 
to the rostro-orbital portion of the head. 
The abdomen is a great elastic sac, which extends behind 
the normally situated vent into the tail; it contains a vast 
collapsed stomach, which extends from its anterior to its 
