336 Miss H. Richardson on the Isopods of the 



VI. EPICAEIDEA, 

 Family XVI. Bopyridse *. 



Body of female primarily disciform, variously modified 

 subsequently by retrogressive metamorphosis ; distinctly 

 segmented ; more or less asymmetrical, twisted now to 

 right, now to left ; dorsal face flattened ; head deeply sunk 

 in thorax and carrying in front two pairs of rudimentary 

 antennte; eyes, when present, dorsal. Maxillipeds lamellar, 

 biarticulate, obtecting the oral area below, and more fre- 

 quently exhibiting a small terminal joint, and, at base, two 

 curved lanceolate appendages. Legs seven pairs, sometimes 

 obsolete on one side, and all of same structure, short, pre- 

 hensile ; coxal plates obsolete or distinctly defined. Incu- 

 batory plates, five pairs, more or less arching over the ventral 

 face of the thorax ; first pair, as a rule, concealed by second 

 and divided by a transversal fold into two segments. Abdo- 

 men more or less distinctly segmented ; pleopoda forming 

 simple or double lamella?, all of the same structure, rarely 

 obsolete. Uropoda when present simple lanceolate. Male 

 elongate, very small, symmetrical ; segments of thorax distinct, 

 those of abdomen sometimes distinct, sometimes confluent. 

 Mouth-parts simple, conic; posterior antenna with flagellum 

 four-articulate; legs of uniform structure; uropoda with 

 inner branch shorter than outer. Parasitic on decapodous 

 Crustacea f. 



This family has not been suflSciently worked up to oflfer as 

 yet any systematic arrangement of the genera \. 



37. Argeia, Dana. 



Analytical Key to the Species of Argeia. 



a. Head transverse. All the thoracic 



branchial appendages present. All 



the abdominal appendages present. . 88. A, puffettensis, Dana. 

 a'. Head bilobate. Thoracic branchial 



appendages apparently absent in 



some of anterior segments. Last 



three pairs of abdominal appendages 



wanting 89. ^. depauperata, Stimpson. 



* Sars, ' Crustacea of Norway,' ii. 1898, pp. 195, 190, pis. xi., xii. 



f 15opyrida3 parasitic on Craiif/on crariffim (Linnanis), Nectucranfjon lar 

 (Owen), Nvdocrantjon ulai^kevsix, Kingsley, and other shrimps, have been 

 reserved for more detailed study. 



X See Hansen, Bull. Mus. Comp. Zool. Harvard College, xxxi. (1897) 

 p. 112. 



