224 
the first hand, with its front margin a little removed from the 
end of the head. Second antennular joint (Pl. V, fig. 1) distally 
with three processes, the anterior of which long and slender, the 
two others much shorter, oblong-triangular. Antennæ short, reaching 
about the hind margin of second thoracic segment; flagellum much 
shorter than the peduncle. The epimera with a small number of 
sharp teeth. First hand thick, only a little longer than broad. Seventh 
hand (Pl. V, fig. 1 d) slightly more than twice as long as broad, 
its digitate setæ respectively with four and five branches — Length 
0/66 mm. 
Occurrence. — In the marsupium of Gastrosaccus spinifer 
Goés from the North Sea. An enormous number of specimens of 
this species of Mysidæ had been taken by the "Thor” 41/2 miles 
N. W. t. W. of Vyl lightship, 15 fathoms, and a good number of 
the females have this parasite in the marsupium. Once I found 
an immature female and three males in the same marsupium; 
sometimes the marsupium contains a young female and a larva in 
the stage described, frequently a more than half-grown or full- 
grown female with its male as described above, and in this case 
sometimes a larva in the second stage. The female is attached 
to the ventral surface of the host, with the front end towards the 
hind wall of the marsupium. 
Remarks. — Both female and male differ much from Dajus 
and are on the whole allied to Aspidophryxus, but show some 
fine differences. 
54. Cyproniscus cypridinæ G. O. Sars 
Cyproniscus cypridinæ G. O. Sars, Account, Il, p. 283, Pl. XCVII, Pl. 
XCVIIL, fg. 1. 
Denne interessante Form lever bagtil paa Ryggen af Legemet 
under Skallerne af den meget store Muslingekrebs Cypridina nor- 
vegica Baird. I de senere Aar har "Thor” taget et stort Materiale 
af Ostracoden i de dybere og dybe Dele af Skagerak, og ved nær- 
mere Eftersyn viste det sig, at en forholdsvis ret betydelig Mængde 
af Exemplarer var infesterede med Snyltekrebsen i et eller andet 
