28 



ParapaCtURUS dimorphus (Studer). 

 1883. Eupagurus dimorphus, Studer, Abhandl, k. Akad, 



Wiss., Berlin, for 1882, Crust. Gazelle, p. 24, t. 2, 



f. 1 1- 1 2. 

 1888. Parapagitria dimorphus, Henderson, Challenger 



Anomura, p 86, t. 10, f. i. 

 1893. Parapagurus dimorphus, Milne-Edwards and Bouvier, 



Mem. Mus. Comp. Zool., Harvard, v. 14, Paguriens, 



P- i^- 

 Front with central convexity flanked by an obtuse tooth 

 on either side, hind border of carapace acutely emarginate ; 

 there are tufts of fine hairs on the surface behind the cervical 

 groove. Eye-stalks somewhat constricted in the middle, 

 according to Studer carrying on the upper surface a narrow 

 longitudinal row of little hairs, a feature which probably 

 becomes more conspicuous with age, as in average specimens 

 it is only with difficulty detected ; the corneae are dilated, 

 distinguishing this species from others as yet known. 

 Ophthalmic scales short, with an apical tooth. First antennae 

 with a tooth at apex of otolithic lobe, the actual apices of the 

 first joint rounded, third joint almost clear of the eyes, distally 

 widened, lower flagellum eight-jointed, about half as long as 

 the upper. The peduncle of the second antennae scarcely 

 reaches beyond the eyes ; the acicle is bordered with a dozen 

 teeth and some slender hairs. The elongate mandibles have 

 the third joint of the palp much longer than the first or 

 second. The third maxillipeds ; the sternum separating them 

 has two median forward pointing teeth ; the third joint is 

 oblong, bordered with [zz] very unequal teeth, of which three 

 are considerably larger than the rest ; the fourth joint is 

 narrow at the base. 



The left cheliped is small, rather hairy, the thumb in 

 line with the trunk of the hand or nearly so, and the 

 finger lying close to the thumb. The right cheliped in 

 the male is greatly elongate, fourth joint on inner side with 

 tuberculate ridge apically rounded, fifth and sixth covered 

 with tubercles, larger ones forming a ridge on inner side of 

 fifth and on both sides of sixth ; a fine down coats parts of 

 these joints, chiefly the outer surface ; the thumb is shorter 

 than the trunk of the sixth joint, from which it bends slightly 

 away ; the carinate, tuberculate finger more or less adapts 

 the irregular tubercles of its inner margin to the intervals 

 between those of the thumb, but there is sometimes a gap 

 left, as shown by Studer, probably, as explained by Dr. 

 Henderson, a character of advanced age. In the female the 

 right cheliped is less elongate, much less strongly tuberculate 

 and without a thumb, the sixth joint not being sufficiently 



