118 Part I1l.—Twenty-jirst Annual Report 
had probably on previous examinations been passed over as being merely a 
form of it. Recently, however, a more careful scrutiny of these smaller 
forms has revealed certain structural differences which render their removal 
from that species necessary, and as this form is distinctly smaller than the 
other, I propose to call the new species Tetragoniceps pygmeus, and the 
following is a description of it :— 
Description of the Female.—The female closely resembles the female of 
Tetragoniceps incertus but is distinctly smaller, measuring only a little 
over *5 mm. (about 7, of an inch). (Letragoniceps incertus is about one 
millimetre in length). The body is very slender, with a small but 
distinct rostrum (fig. 11). 
Antennules almost similar to those of Tetragoniceps incertus, differing 
only to a small degree in the proportional lengths of the different joints 
(fig. 12). The antenne and mouth organs are also very similar. 
The first four pairs of thoracic feet are also very similar to the same 
appendages in Tefragoniceps incertus, but the first pair are rather more 
slender, especially the inner branches, while the seta on the inner margin 
of the first joint appears to be situated nearer the middle of it, the outer 
branches appear also to be proportionally rather longer (fig. 14). 
The fifth pair (fig. 16) are not only smaller, but differ in form and 
armature ; they are more bluntly rounded at the apex, and instead of 
terminating in a single stout apical spine as in the species referred to, there 
is at the base of the larger spine another one, small but distinct ; the 
arrangement of the supplementary setee is also different in the two species, 
as shown by the drawings. 
The furcal joints, which are somewhat dilated in the middle, taper 
towards the distal end; the principal apical seta of each furcal joint is 
moderately short, and the outer portion of it terminates somewhat 
abruptly, but is continued by a slender portion which forms a peculiar 
loop where the two portions join, as indicated by the figure; this 
peculiarity is not found in Tetragoniceps incertus (fig. 19). 
The male resembles the female, except in the following particulars. The 
antennules (fyg. 13) are modified for grasping, they differ slightly from 
the male antennules in Tefragoniceps incertus. 
The inner branches of the third pair of thoracic feet (fig. 15) are small 
and three-jointed ; the first and second joints are very short, but the inner 
part of the second is produced into a long bent spiniform process which 
extends considerably beyond the extremity of the branch ; the last joint 
is also small and bears a minute terminal spine. In Tetragoniceps incertus 
this branch has a long straight process arising from its inner basal aspect 
and is furnished with two terminal sete. 
The fifth pair are smaller than those of the female, they also differ in 
their armature as shown by the drawing (fig. 17). The supplementary 
foot om the first abdominal segment is furnished with three setz (fig. 18). 
Remarks.—This form, though perhaps it does come somewhat near to 
Tetragoniceps incertus, is not difficult to distinguish from that species, 
even without dissection, by its smaller size and by the difference in the 
character of the fifth feet and the furcal joints, and these differences are 
of course more easily observed when one has both forms under observation. 
Genus Laophonte, Philippi (1840). 
Laophonte gracilis, T. Scott, sp. nov. Pl. vi., figs. 6-12. 
Description of the Female.-—The body is slender and sub-cylindrical, 
and appears to be covered with exceedingly minute hairs. It has a small 
blunt rostrum, and the furcal joints are scarcely so long as the last 
