962 DR. H. J. HANSEN ON CRUSTACEANS [Dec.1, 
8. vigilaw, Stimps., H. J. H.—Only the Mastigopus has been 
described (see later on). The adults of this and the next species, 
S. penerinki, Bate, H. J. H., are very closely related to each 
other aud easily separated from S. icertus, n. sp., and S. halia, 
Fax., by the character, that on the ext. br. of urp. the ciliated part 
occupies between + and 7 of the exterior margin. The best 
character between S. vigilav and S. penerinki is that in S. vigilaa 
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. penerinks 
the sixth joint is armed with ec. 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. vigilaw the rostrum is 
of medium length, strongly laterally compressed, seen from the side 
rather broad and apically 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 specimeus of adults and larve from the Atlantic north- 
ward to lat. 42° N.; in the Indian Ocean the larve are common 
and distributed eastward to lat. 24° 50’ 8., long. 103° E. 
S. penerinki, Bate, H. J. H.—Only the Mastigopus has been 
described (see below). The rostrum of the adult is somewhat 
elongated, seen from the side a little more narrow than in 
S. vigilav and from the middle tapering towards the acute apex. 
The chief character in the structure of mxp.’ is given under 
S. vigdax.—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 
Kroyer as a variety of S. edwards. 
S. incertus, n. sp.—Only one adult specimen, a female, has been 
seen, but this is a giant in comparison with the other related 
species, being 47 mm. long. On the ext. br. of urp. the ciliated 
part occupies between 3 and 7 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 one 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, pl. li. 
figs. 1-le). 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. 2138: “The first and second 
segments of the antennule are of about equal length, while the 
