1996.] OF THE GENUS SHRGHSTES. 953 
which, from the spina on the outer margin, is strongly tapering 
towards the apex, the outer margin even being slightly concave in 
outline ; the sixth joint of mxp.’ is distinctly 4-jointed, the relative 
length of these subjoints as in the larva (see below). Above trl.’ 
a well-developed pleurobranchia and a lamella, above trl.* a well- 
developed pleurobranchia and a lamella with 2-5 branches at the 
tip, thus a branchia very little developed and more feeble than in 
any other adult species known to me. 
S. longispinus, Bate (p. 417, pl. Ixxvi. fig. 2), is most decidedly 
the larva of S. cornutus, Kr. It attains a length astonishing as 
compared with that of the adult. The specimen which I am 
about to describe is 13 mm. long, while the adult male is but 16 
mm. ‘The rostrum is somewhat longer than in the adult, without 
dorsal spine, the supra-ocular and the hepatic spines and the 
gastro-hepatic groove are well developed. The eye-stalks are very 
long, the large, somewhat oblique eyes lie above the basis of the 
third joint of the antenn. ped., the relative length of which is 
almost as in the adult. Mxp.’ is but little longer than trl.* and 
constitutes in several respects a transition-form to S. edwardsi, 
Kr., and allied species; the first joint is considerably incrassated, 
second—fourth joints but little coarser than in trl.*, the fourth joint 
with very few and short bristles, the fifth with few sete more 
developed on the one than on the other margin, the sixth joint as 
long as the fifth (a character also found in S. atlanticus, ete., while 
in the edwardsi-group the fifth joint is much longer than the 
sixth), divided into 4 subjoints, of which the first is 2 times longer 
than the second, and this is as long as the last 2 subjoints together, 
which are about equal in length, or the third somewhat longer 
than the fourth; the 3 proximal subjoints each with very few 
short sete, and at the end with 2 very long stiff sete or slender 
spines, the fourth subjoint with one short and 3 very long apical 
spines, which, however, are scarcely more robust than those on 
trl.’ or trl.’, trl.* reaching a little beyond % of the fourth joint of 
trl. Above trl.* a well-developed branchia and a lamella with 3 
short apical branches. The 3 anterior abdominal segments each 
with a rather short dorsal spine, which, at least on the 2 anterior 
segments, is directed obliquely forward, the fourth segment with- 
out any spine and the fifth and sixth each with a short spine; the 
4 anterior segments having on the middle of each epimeron a spine 
directed outwards, the spine being short on the three segments 
and somewhat longer on the fourth, the fifth segment with a very 
long spine directed downwards and bending somewhat forwards, 
and issuing from the inferior margin at a short distance from its 
posterior end; the sixth segment with a small spine turned down- 
wards from the posterior edge. As in the mature form, the 
ciliated part occupies between 4 and j of the exterior margin of 
the ext. br. of urp. 
The specimen described differs considerably from the figure 
given by Bate, but the form described by him is somewhat 
younger. My determination is decidedly correct, as two similar 
