189 
Mysidion, occurred two parasites, one of which — a female with twelve ovisacs — was 
placed to the front on the carapace, a little to the left of the median process, the other — 
a female with three ovisacs — was placed on the dorsal side of the last thoracic segment. 
On a young individual without marsupiun appeared two parasites, one of them — a female 
without eggs — nearly in the centre of the back of the second abdominal segment, the 
other, a female with two males hinged by their frontal threads (fig. 3c), somewhat to the 
right side on the back of the first abdominal segment. In a hardly adult female (from IKvals), 
on the dorsal part of the second abdominal segment (fig. 3b), I found an adult female with 
two minute ovisacs without eggs, and four larve (v), one of which fell off on being touched, 
so that it was not drawn in fig. 3b, but it is the specimen represented in fig. 3m with an 
adult male beneath the larval skin. 
5. Er. abyssorum G. O.S. On a female with empty marsupium: five parasites, viz. 
two very small females on the right side of the thorax close behind the carapace; and at a 
short distance in front of these animals, on the carapace itself, one small and one good-sized 
female, to the latter of which was attached near its mouth a strongly impaired male with 
a large spermatophore, and the anterior half of another male was fixed by a thread to the 
side of the trunk; finally: at the centre of the dorsal surface of the sixth abdominal segment, 
a good-sized female (fig. 3f and fig. 3g) — all parasites without ovisacs. In a female (from 
Kval6o) with Mysidion abyssorum in its marsupium, occurred five parasitic females, all on 
the carapace; one of them, which was very small, was situated somewhat behind the middle 
of and a little above the left lateral margin, the four others were placed close together at 
some distance behind the centre on the back and a little down on the right side; one of 
these was very small, the two others a little larger, the fourth large, without ovisacs, but 
with two larve attached to it. On an adult male (fig. 3a) appeared altogether nine parasitic 
females and one larva: one female (a) with six ovisacs is placed on the left hand side of 
the carapace; somewhat behind it and further up towards the back, the larva (1) is situated; 
in an irregular transverse row on the dorsal side of the first abdominal segment are found 
altogether five females, one of them pretty small, the four others large(a), two of them each 
with one, the two others together with many ovisacs, which can scarcely be counted accu- 
rately without a dissection; on the back of the second abdominal segment is placed a female 
with seven ovisacs, as well as a male (m) hinged to the female by a long thread, which 
had the larval skin on its anterior end; to the right of the latter large female is found a 
very small female, and on the boundary between the second and the third abdominal 
segment, a tolerably small female (in the illustration the last two specimens are marked b.) 
REMARKS. I must consider the parasites on all five species as belonging to the 
same species. In the females of the four smaller species of hosts, the distance between 
the genital apertures is from much to a little smaller than the diameter of each ring, in 
not full-grown individuals of the largest specimen, Er. abyssorum, this distance varies from 
being a little shorter than to about the same length as the diameter, but in the adult spe- 
