CRUSTACEA COPEPODA. II. 71 
B. Parasites on Cumacea. 
89. Sphzronella decorata H. J. H. 
1897. Spheronella decorata H. J. Hansen, Choniostomatide, p.150, Pl. VIII, figs. 3 a—30; Pl. IX, figs. 
I a—I b. 
Among the new material is found a pupa, a stage unknown of the present species. It is slightly more 
than 0.1 mm. long and similar to that of S. zmsignis H. J. H. described in the book quoted, differing only 
in being somewhat longer than broad, and possessing on the front end a somewhat short thread with a couple 
of thickenings; its whole surface its clothed with rather short hairs excepting on the protruding pouches 
representing antennule and all the mouth-parts. 
Occurrence. — Taken by the “Ingolf’’ at a single station. 
Davis Strait: Stat. 28: Lat. 65°14’ N., Long. 55°42’ W., 420 fathoms, temp. 3°5; 2 specimens of 
Diastylis Rathkei Kr. with parasites in the marsupium. On one specimen: 1 female 
and I male; on the other: 1 female and 1 pupa. 
S. decorata was established on material found in the marsupia of six specimens of Diastylis Rathkei Kr. 
from West Greenland, without special locality. Further particulars on the contents of each marsupium of 
these hosts are given op. cit. p. 152—53. 
Distribution. — Kara Sea, on D. Rathke: Kr. (H. J. Hansen). 
90. Spheronella rotundata n. sp. 
(Pl. V, figs. 4 a—+4 f). 
Female. — An adult specimen (fig. 4 a) is 0.8 mm. and 0.94 mm. broad. The head is well defined 
from the trunk; its front margin (fig. c) is very broadly rounded, naked, and the area between that margin 
and the antennule and rostrum is simple. — Antennule (figs. 4c—4d) well developed, 3-jointed, with 
some setze of moderate length; second joint a little shorter than the first or the third. — Antenne wanting. 
— Mouth middle-sized. — Principal branches of the maxillule short; additional branch not discovered 
with certainty. — Basal joint of the maxillz short, with some few, short filaments at the distal connecting 
membrane; second joint well marked from the claw. — Maxillipeds middle-sized; the proximal joint some- 
what slender and without bristles; second and third joints coalesced, with a pubescent spine near the end; 
last joint pubescent towards the obtuse end. 
The submedian skeleton moderately developped, and two pairs of ridges could be discerned. — 
The lateral margins of the head and the whole trunk naked. — Genital area (fig. 4 e) very much narrower 
than the head and much broader than long, with its median longitudinal part chitinized, and from this 
originates between the posterior part of the genital apertures a pair of chitinized plates, each of which runs 
somewhat backwards and then outwards and forwards as an arch, and serves for the fixation of the muscula- 
ture opening the genital aperture; these apertures are rather near each other and proportionately long. — 
The caudal rami are extremely small and placed at the base of the median thin skin between the origin of 
the chitinized plates mentioned. 
