201 



smooth or tuberculated. Uropoda distinct, forming a pair of simple lanceolate 

 lamellse. Male with all the segments of the body well defined. Parasitic in the 

 branchial cavity of Anomura, Macroura and Carida. 



Remarks. From the 2 preceding genera, the present genus is clearly distin- 

 guished by the presence in the female of distinctly defined coxal plates, of rather 

 fully developed pleopoda, and of distinct though simple uropoda. Moreover, the 

 incubatory plates are much larger, so as to encompass the marsupial cavity more 

 or less completely. Finally, the metasome of the male is as distinctly segmen- 

 ted as the mesosome. Several species of this genus have been established, some 

 of which, however, are referred by M.M. Giard and Bonnier to their genus 

 Palcegyge. To the fauna of Norway belong 9 species, to be described below. 



i. Pseudione af finis, G. 0. Sars. 



(PL LXXXV, fig. 1). 



Pleuroorypta ajfinix. G. 0. Bars. Oversigt over Norges Crustaceer I, p., 68, PI. 2, figs. 7, 8. 



Syn. : Palcegi/ge affinis, Giard & Bonn. 

 Hoi/lii, Giard & Bonn. 



Specific Characters. Body of female but slightly asymmetrical, oblong 

 oval in outline, with the greatest width in the middle. Cephalon semicircular, 

 convex above, and encircled in front by a broad arched lamella. Segments of 

 mesosome very sharply defined in the middle, lateral parts distinctly bilobed, 

 anterior lobe somewhat elevated and transversely truncated at the tip, posterior 

 narrowly rounded ; coxal plates distinctly projecting, lamelliform. Metasome 

 comparatively short, but rather broad, epimeral plates rounded, sub-imbricate ; 

 last segment very short. Eyes distinctly perceptible, though very small and 

 simple in structure. Terminal joint of maxillipeds well defined, narrow, incurved, 

 setous on both edges. 1st pair of incubatory plates with the terminal lobe 

 straight; the succeeding pairs not completely overlapping each other in the 

 middle. Legs more fully developed than in most other species, and distinctly 

 projecting on each side. Pleopoda with the lamellse quite smooth and partly 

 projecting beyond the edges of the epimeral plates. Uropoda resembling in 

 size and structure the lamellse of the pleopoda. Male rather broad, depressed, 

 not nearly 3 times as long as it is broad, metasome not abruptly contracted, 

 last segment minutely bilobed. Colour of female (according to notes left by 

 my late father) whitish, with the incubatory plates dark brownish violet at their 

 bases, somewhat lighter in their outer part; colour of male light yellowish. 

 Length of female 10 mm., of male 2 mm. 



26. Crustacea. 



