962 DE. n. J. HANSEN ok chustaceans [Dec. 1, 



S. vigilax, Stimps., H. J. H. — Only the Mastigopus has been 

 described (see later on). The adults of this and the next species, 

 S. yenerinlci, Bate, II. J. H., are very closely related to each 

 other and easily separated from S. incertus, n. sp., and S. halia, 

 Pax., by the character, that on the ext. br. of iirp. the ciliated ])art 

 occupies between ^ and g of the exterior margin. Qlie best 

 character between S. vigilax and S. jienei-inJci is that in S. vii/ila.v 

 the interior margin of the sixth joint of mxp.'' is armed with 22-25 

 spines, of which 4 are implanted on the third subjoint, which is 

 but a little or scarcely shorter than the fourth ; in S. penerinki 

 the sixth joint is armed with c. 15 spines (the apical one as usual 

 not included), of which but two on the third subjoint, which is con- 

 siderably shorter than the fourth. In S. vicjilax the rostrum is 

 of medium length, strongly laterally compressed, seen from the side 

 rather broad and apieally more or less distinctly truncated, with 

 an acute prolongation from the superior edge. — Length 16-27 mm. 



This species is as common as S. edwardsi, Kr. ; I have seen 

 numerous specimens of adults and larvfe from the Atlantic north- 

 ward to lat. 42° N. ; in the Indian Ocean the larvse are common 

 and distributed eastward to lat. 24° 50' S., long. 1 03° E. 



S. penerinki, Bate, H. J. IT. — Only the Alastujopvs has been 

 described (see below). The rostrum of the adult is somewhat 

 elongated, seen from the side a little more narrow than in 

 S. vigilux and from the middle tapering towards the acute apex. 

 The chief character in the structure of mxp." is given vmder 

 /S. vigilax. — Length c. 18"5 mm. 



I have seen but two adult specimens, the one captured at lat. 17° 

 N., long. 22° W., and this is one of the specimens alluded to by 

 Kriiyer as a variety of S. edwardsi. 



S. incertus, n. sp.- — Only one adult specimen, a female. Las been 

 seen, but this is a giant in comparison with the other related 

 species, being 47 mm. long. On the ext. hr. of urp. the ciliated 

 part occupies between 3 and 5 of the exterior margin. The first 

 joint of the antenn. ped. is scarcely shorter than the third. The 

 rostrum is somewhat elongated, strongly compressed ; seen from 

 the side the proximal half is rather broad and then it tapers 

 towards the acute apex. The interior margin of the sixth joint of 

 mxp.* with but 13 spines, two of them on the third and orie on the 

 fourth subjoint, which is but very little longer than the third. 

 The other characters are mentioned above. 



The adult specimen was captured (on the surface) in lat. 34° 50' 

 S., long. 4° 30' W. ; a sub-adult specimen near that locality, and a 

 larva in lat. 40° 4' S., long. 53° 20' E. 



<S. halia. Fax. — The specimens on which this species was estab- 

 lished in 1893 are just the large specimens described and figured 

 by Faxon in 1895 as a variety of S. edwardsi, Kr. (p. 212, pi. 11. 

 tigs. 1-1 e). This species, of which I have seen no specimen, is 

 closely related to S. incertus, m., but disagrees in one character, 

 about which Faxon writes, p. 213: "The first and second 

 segments of the antenuule are of about equal lengdi, while the 



