203 
Figure 2. Mysidion abyssorum n. sp. 
2a. Head of female, < 182; a. antennula, e’. additional branch of the maxillula. 
2b. Genital aperture and the surrounding skeleton of female, >< 123; g. genital aperture, A. plate 
formed of a kind of viscous substance and covering the lips of the genital aperture and the 
skeleton behind them, 7. stalks of ovisacs, the basal parts of which are confluent and form 
the plate mentioned, & hole (or very small thin-skinned area with minute holes) at the 
anterior end of the skeleton, 
2c. Male, 43. 
2d. Very small male with frontal thread, > 43. 
2e. Normal male seen from below, >< 256; e. maxillula, g. spermatotheca, w. line of unknown 
nature, 
2 f. Normal male seen from left side, * 236; a. conical eminence on the dorsal side of the head. 
2g. Frontal thread of one of the minute males, 260. 
2h. Larva seen from below, 264. The natatory legs are omitted. 
2 i. Hinged larva seen from above, X 125. 
3. Aspidoecia Normani Giard and Bonnier. *) 
3a. Male of Hrythrops abyssorwm G. O. Sars seen from above and infested with nine female parasites 
of very different size and one larva, >< 1%/2; a. larger female, b. smaller females, 7. larva, 
m. mnale. The posterior part of the abdomen of the host is omitted. 
3b. Female with two rudimentary ovisacs (w.) and three larve (v.) attached to the dorsal surface 
of the second abdominal segment of Erythrops serratus G. O. Sars, >< 24; 7°. chitinous knots 
where the entrances to the receptaculum seminis must be found. 
3c. Sub-adult female attached to the back of the first abdominal segment of an Er. serratus and 
seen from the dorsal side, >< 39; x. two males hinged by their frontal thread, y. part of the 
skin of the host. 
3d. Head of a female from Er. serratus, seen much from in front, >< 350; d. mouth, e. maxillula, 
s. adhesive plate, ¢. internal space possessing a peculiar refraction of light. 
3 e, External genital organs and receptaculum seminis of the female whose head is shown in fig. 3d, 
< 70; e. solid ring, g. genital aperture, /. hole in the ring, 0. chitinous knots, 7. receptaculum 
seminis with its ducts. 
3 f. Adult female from Er. abyssorum, >< 24; the head is seen in the middle. 
3g. The same male seen from the side opposite of that of fig. 3f; r. ring around a genital aper- 
ture, 7’. chitinous knots. 
3h. Head of the female shown in the two preceding figures, cleaned with caustic potash and seen 
from below, 350; @. antennula, 
3 i. Genital aperture and its surroundings of the female shown in fig. 3f, > 170; e. ring-shaped 
skeleton, f’. less solidly chitinised part of the ring, g. genital aperture with its lips, #. hole 
in the ring, m. muscles. 
3k. Male from Er. serratus seen from below, >< 291; 6. olfactory seta of the antennula, g. sper- 
matotheca. (In other specimens two spermatothecee were found.) 
3]. Another male from Ey. serratus seen from left side, >< 324. 
1) On the plate is written Normanni instead of Normani. 
26° 
