241 



Munnoniscus marsupialis, G. 0. Sars. 



(PL XOIX, fig. 2.) 



Cryptothiria marsupialis, G. O. Sars, Ovei-sigt over Norges Crustaceer I. p. 74, PI. 2. fig. 22 23. 



Syn : Munnoniscus Sarsii, Giard & Bonnier. 



Specific Characters. Body of adult female nearly as broad as it is long, 

 somewhat narrower in front] than behind, and divided behind into two lateral 

 lobes of somewhat unequal size, the right lobe generally advancing beyond the 

 left, from which it is defined by a deep and narrow incision, in front only by a 

 slight sinus; dorsal area comparatively small, diamond-shaped. Younger female 

 more symmetrical in form, regularly bilobed behind, and obscurely trilobate in 

 front; dorsal face convex and slightly wrinkled, ventral flattened, with a slight 

 groove along the middle. Length of adult female 2 ] /2 mm. Parasitic on Eurycope 

 cornuta G. 0. Sars and Ilyarachna longicornis G. 0. Sars. 



Remarks. As above mentioned, this is the only species of the genus as 

 yet known, for the form named by MM. Giard and Bonnier M. Sarsii does not 

 in reality differ in any respect from the type species, except by its occurrence 

 on a different species of Munnopsidce. The male and last larval stage I have 

 not succeeded in finding; but the embryos (see fig. 2 emb.) are fully normal, 

 exhibiting all the features found in other Epicarida. 



Occurrence. I have found this extremely degenerate parasite in the marsu- 

 pial pouch of 2 different Munnopsidce, viz., Eurycope cornuta G. 0. Sars and 

 Ilyarachna longicornis G. 0. Sars, more frequently in the former than in the 

 latter. In both instances the incubatory lamellae of the host were fully deve- 

 loped, and the parasite must accordingly have entered the marsupium immediately 

 after the young of the host had escaped. 



Gen. 6. LlriOpSlS, Mac Schultze, 1859. 



Syn. : Liriope, Rathke. 



Ci-yptothiria, Sp. Bate (part). 



Generic Characters. Body of adult female consisting of two very sharply 

 defined sections connected by a narrow neck, the anterior deeply immerged within 

 the body of the host, the posterior freely exposed, the former showing traces of 

 segmentation, the latter quite simple. No trace of any appendages or affixing 



31. Crustacea. 



