958 DR. H. J. HANSEN ON CRUSTACEANS [ Dec. 1; 
times shorter and very narrow ; the first branchia above trl.4 is but 
half as large as the corresponding one above trl.*, the second half 
as large as the first but a little larger than the second above trl.’. 
(In somewhat younger specimens with yellowish eyes all 4 branchiz 
are very distinct; the animals are, for the rest, relatively shorter 
and stouter.) The ext. br. of urp. without any spine on the 
exterior margin, of which the ciliated part occupies from a little 
more than the half to about three-fifths of the length. 
As to the half-grown larvee, the representations of Kréyer and 
Bate will be sufficient—A younger larva, 6-4 mm. long, coincides 
fairly well with S. wtrinquedens, Bate (p. 483), in most respects, 
but yet differs in several particulars from Bate’s description. 
The supraocular and hepatic spines are well developed; the 
rostrum is almost as long as the eye-stalks (the eyes not included), 
with a short and fine dorsal spine at the base ; the eyes are much 
larger and the eye-stalks longer than in the stage described by 
Kroyer and Bate. The third jomt of the antenn. ped. is but a 
little longer than the second, and the first one as long as the two 
others taken together. The fourth to sixth abdominal segments each 
with a very short and fine dorsal spine, the epimera of the first to 
fourth segments each produced into a short spine, while this spine 
is considerably longer on the epimera of the fifth segment; the 
first segment besides on the side having a spine arising from the 
anterior margin and directed forwards and outwards. On the 
ext. br. of urp., which is almost seven times-longer than broad, the 
ciliated part occupies a little more than the half of the exterior 
margin, which—as in almost all young larvee—is furnished with a 
well-developed spine. 
Of S. corniculum, Kr., I have seen numerous specimens from the 
Atlantie northward to lat. 42° N., from the Indian Ocean and 
ranging into the Pacific to the Matelota Island and to lat. 16°10’ N., 
long. 132° E. 
Whether the above-quoted S. utrinquedens, Bate, may be a young 
larva of S. corniculum, Kr., or of another species I am not able to 
decide. 
S. longirostris, Bate (p. 415, pl. Ixxy. fig. 3).—Prof. C. Chun 
has determined the small stage of S. corniculum, Kr., just described 
as S. longirostris, Bate, which is stated to be 6 mm. long and cap- 
tured in “ Mid Atlantic,” and it is very possible that this determi- 
nation may be correct ; but Bate’s figure represents the eye-stalks 
and the rostrum a little too long, and especially a different proportion 
between the joints of the antenn. ped. &c. I believe that it is 
impossible to decide whether this identification is correct. 
Above I have further enumerated 5 species belonging to Group I. 
Of these species S. precollus, Bate (p. 423, pl. xxvii. fig. 2), is at 
least rather nearly related to S. corniculum, Kr., from which it 
seems to differ by a somewhat different shape of the ext. br. of urp. 
and by having the fifth abdominal segment “ dorsally produced to 
a point.” 8. longicaudatus, Stimps. (p. 46), is a larva perhaps 
belonging to the arcticus-group. On the three other species, all 
larve, I have no opinion. 
