Figure 
eae 
ab. 
3) 
° 
| b. 
202 
8. Choniostoma Hansenii Giard and Bonnier (continued). 
Adult female, 79/4. 
Small female,  ?9/s. 
Ovisac, xX 79/4. 
Head of an adult female, 130. 
Part of the skin of the ventral side outside the head of a small female, 130. 
Genital area of an adult female, >< 128. 
“N 
3. Mysidion commune n. gen., n. sp. 
The contents of the marsupium of an Evythrops s rratus G. O. S. seen from below and con- 
sisting of the female parasite with ils seventeen ovisacs, >< 12. 
Another female with its ovisacs from Hr. serratus seen from above (the head situated on the 
dorsal side and its front turning backward), 
only in three of the thirteen ovisacs. 
25; g. maxillipeds. The contents indicated 
Four ovisacs of another female, >< 25. In the largest ovisac only a small part of the con- 
tents, namely six larve, are drawn. 
Male, X< 25. 
Posterior half of the ventral surface of female, >< 42; e. skeleton surrounding one genital 
aperture; 7. transition between the receptaculum seminis and one of its ducts, s. spermatophores. 
Left genital aperture with its lips, muscles and the surrounding skeleton seen from below, >< 190. 
Male seen from below, > 258; g. spermatothecw. The hair-covering of the trunk drawn 
only on one side. 
Another male seen from left side, >< 258; s. frontal thread, ¢. part of a marsupial plate of 
the host, a. conical eminence on the dorsal side of the head. 
Very small pupa seen from below, >< 188; 2. outline of a mouth (?) beneath the skin of the 
pupa. — This and all the other figures of this parasite are drawn from animals taken on 
Erythrops serratus GO. S. 
PLATE XII. 
1. Mysidion commune n. gen., n. sp. (continued). 
Head of female, > 182; a. antennula, w. process of unknown nature (perhaps. stiffened 
viscous substance on the opening of the gland producing it). 
Pupa with. dorsal thread, > 25. (The same enlargement as in fig. 3b—3d on pl. XI.) 
Pupa seen obliquely, >< 182; a. (misseript for ¢.) antenna, f. maxilla, g. maxilliped, 7. skeleton 
surrounding the future genital aperture, ¢. (misscript for a.) antennula, w. basal part of the 
dorsal thread shining through the animal, ». distal part of the thread, x. eminence at the 
mouth of the pupa stage, y. mouth of the pupa stage, y’. chitinous lists on the side of the 
rostrum of the pupa. The mouth and the maxillule of the young female are seen at the 
anterior end of the animal. 
Very young female in possession of characters which it loses afterwards, >< 182; a. (misscript 
for ¢.) antenna, 7. skeleton surrounding the future genital aperture, ¢. (misscript for @.) anten- 
nula, wv. basal part of the dorsal thread, v. distal part of the dorsal thread, a. odd ventral 
process situated at the place of the mouth of the papa stage, 2. body of unknown nature, 
