258 A HISTORY OF RECENT CRUSTACEA 
and broad tridentate frontal plate, and leaves the last 
segment of the trunk dorsally uncovered. ‘The scale of 
the second antenne is broad and heart-shaped with a 
fringed inner margin. The elongate telson terminates in 
some strong spines and a little serrate plate. 
Ceratolépis, G. O. Sars, 1883, has also only one species, 
Ceratolepis hamata, which much resembles the preceding, 
but its hard and large carapace leaves no segment of the 
trunk uncovered. The scale of the second antenne is 
narrow and flexuous, forming a sort of hook on either 
margin, with no fringe of hairs, and the telson is not 
truncate at the apex but cleft into two diverging lappets, 
‘somewhat resembling the tail of a swallow.’ The single 
specimen was scarcely half an inch long, and hence the 
smallest of the known Lophogastridz, and, though its 
organisation seems to mark it out as a deep-sea form 
like the rest of the family, it was in fact taken at the 
surface of the Pacific. 
Gnathophausia, v. Willemoes Suhm, 1879, has a 
parchment-like integument, the carapace in front drawn 
out into a long spear-shaped and denticulate rostrum, and 
behind in general into a backward pointing spine. ‘The 
greater part of the carapace, as in the genus Nebalia, 
would appear to form, so to speak, merely a loose mantle 
arching the back and sides of the trunk, and within which 
the body is freely movable.’ This part is surmounted by 
two longitudinal keels on each side. On the upper side 
of the eye-stalk there is always a small prominence called 
the ocular papilla. Of the first antennz the outer 
flagellum is very long and so compressed as to be almost 
ribbon-shaped. The scale of the second antenne 1s 
variable. The first maxilla have on the outer side of the 
basal part a two-jointed ‘palp,’ which, contrary to what 
is the case in the other Podophthalma, is bent directly 
backwards. Though looking like an epipod, this appears 
to be part of the endopod. Both joints are armed with 
setee or bristles, those on the second joint elongate, the 
apparatus being no doubt destined to sweep the branchial 
cavity, as is the case with the similar formation in the 
