70 DR. H. J. HANSEN ON CRUSTACEANS [Jan. 20, 
SERG. VENTRIDENTATUS Bate, p. 431 (no figure). 
Bate gives the locality “north of the Sandwich Islands” and 
the length “7 mm.” <A specimen labelled in accordance with the 
text is preserved in balsam; it is a young S. oculatus Kr., the 
Mastigopus of S. edwardsti Kr. 
SERG. UTRINQUEDENS Bate, p. 433 (no figure). 
Bate gives the locality “ North Pacific Ocean,” and the length 
“3:5 mm.” Nospecimen could be found in the collection. Bate’s 
specimen is a very young J/astigopus ; in my earlier paper I 
have placed it near S. corniculum Ky., but a final interpretation 
is Impossible to me. 
SERG. DISSIMILIS Bate, p. 437 (no figure). 
Jn the collection one specimen, from Cape Verde Islands, is 
preserved; it is certainly the type described by Bate. In my 
earlier paper I had determined it as one of the larval stages of 
S. arcticus Kr., but this is not correct. The rostrum is siightly 
more than one-third the length of the eye-stalks, its basal part 
somewhat ascending, with a very small spine on the upper angle, 
its distal part 1s a slender horizontal spine. The hepatic spine 1s 
short. The eyes are only a little higher than the distal end of 
the eye-stalks, and these increase gradually in thickness from the 
base outwards. In the antenn. ped. the distal half of the first 
joint has the margins nearly parallel, and the two other joints are 
a little thicker than in the corresponding Mastigopus of S. arcticus. 
Fourth to sixth abdominal segments each with a very small dorsal 
spine directed backwards; the spine on the sixth segment is the 
longest. The ext. br. of urp. is almost, but not quite, five times 
longer than broad. All these characters agree with those found 
in a Mastigopus of S. mediterraneus H. J. H. preserved in the 
Copenhagen Museum ; and sketches drawn in London of the shape 
of the distal part of the squama and the telson agree also with 
the last-named form. I must therefore consider S. dissimilis Bate 
as identical with S. mediterraneus H.J.H. The result is that 
the last name must be withdrawn as a synonym, and the species, 
of which the sub-adult stage has been described in my earlier 
paper, must be called S. dissimilis Bate, H. J. H. 
II. Some Results of the Investigation. 
In my earlier paper on Sergestes I have paid as much attention 
as possible to the animals described by Bate; in nearly all cases 
I was able to state whether the specimen was an adult form or a 
Mastigopus, and several of the species were interpreted. After 
the study of the material preserved in the British Museum, I have 
now been able to confirm most of my earlier statements, to 
interpret an additional number of the specimens mentioned by 
Bate, and to correct two faults committed by myself. I had 
erroneously referred S. dissimilis Bate to S. arcticus Kyr., instead 
of identifying it with S. mediterranews H. J, H. (see above). 
