Dr. IT. J. Hansen on a yieio Species of Sergestes. 479 



LXVII. — On a new Species of Sergestes obtained by Mr. 

 George Murray during the Cruise of the ^Oceana ' in 1898 *. 

 By Dr. H. J. Hansex, of Copenhagen. 



Sergestes inermis, sp. n. 



Locality. Lat. 52° 4'-5 N., long. 12° 27' W. Net no. 2/. 

 620 fath. 19/11/98. 



A single rather mntilated specimen which measures 

 24 millim. from the end of the rostrum to the tip of the 

 telson. It seems to be rather far from full-grown, but its 

 eyes are quite black, as in mature specimens of other species. 



The rostrum (fig. 1, p. 480) is of medium length, directed 

 forwards and somewhat upwards, its apex produced as a small 

 horizontal si)ine, at the base of which the upper margin shows 

 a rudimentary projection. Supraocular and hepatic spines are 

 wanting, the gastro-hepatic groove is rather developed. The 

 eyes (figs. 1 and 2) are moderately large, a little shorter than 

 the distal joint of the eye-stalks and somewhat broader than 

 long. The peduncles of the antennulse have their basal 

 joint somewhat shorter than the two other joints together ; 

 the second joint is slightly more than twice as long as deeji, 

 seen from above its inner margin is two and a half times 

 longer than its breadth and a little longer than that of the 

 third joint ; the third joint is rather thick, seen from the 

 side as deep as the second and slightly more than twice as 

 long as deep, seen from above a little more than two and a 

 half times longer than broad. The antennal squama is 

 distally broad (fig. 2). The pleurobranchise (fig. 3) of the 

 second thoracic leg and the first one of the third leg arc 

 long ; the second branchia of the third leg is well developed, 

 but not quite two thirds as long as the first, and nearly as 

 long as the anterior branchia of the fourth leg, and this is 

 somewhat longer than the posterior branchia. The maxillipeds 

 and the four anterior pairs of thoracic legs have been broken 

 off. The last pair of legs are as long as the peduncles of the 

 antennulse, narrow; the penultimate joint (fig. 4) about six 

 times longer than broad. The external branch of the 

 uropods is four and a half times longer than broad (fig. 5), 

 its spine situated slightly beyond the proximal two thirds of 

 the margin. 



This species is rather closely allied to ;S^. robustus, Smith 

 (Bull. Mus. Comp. Zool. x. 1882, p. 97, pi. xvi. figs. 5-8 Z»), 



* See Journ. Geo|?rapIi. Soc. vol. xiii. no. 2, Feb. 1899, where the 

 method of capture by a series of opeu tow-nets is described. 



