1896.] OF TUB oiaN0S seegbstbs. 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-iointed, 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, pi. Ixxvi. fig. 2), is most decidedly 

 the larva of S. cormUus, 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 10 

 mm. The rostrum is somewhat longer than in the adult, without 

 dorsal spine, the supra-ocular and the hepatic spines and the 

 gastro-hepatlc 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 seta3 more 

 developed on the one than on the other margin, the sixth joint as 

 long as the fifth (a character also found in S. atlanticns, etc., while 

 in the cdwardsi-gron-p the fifth joint is much longer than the 

 sixth), divided into 4 subjoints, of which the first is ^ 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 fourtli ; the 3 proximal subjoints each with very few 

 short setse, and at the end with 2 very long stifi' setee 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 siiort 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 -J- and | of the exterior margin of 

 the ext. br. of urp. 



The specimen described difEers considerably from the figure 

 given by Bate, but the form described by him is somewhat 

 younger. My determination is decidedly correct, as two similar 



