454 0. 0. SARS. 



bined, aud lias the doi-sal face strongly vaulted, for which reason this spe- 

 cies acquires a rather peculiar physiognomy. In its interior numerous strong 

 muscular bundles are seen converging to the buccal area, and the points of 

 insertion for these bundles beneath the integument produce a peculiar areo- 

 lated appearance of the dorsal face of the head. The lateral lobes are very 

 short and broad, being transversely truncated at the tip. Behind them the 

 inferior edges of the head form a deep emargination encircling the globular 

 basal joint of the inferior antennae. 



The anterior pairs of coxal plates are not particularly large, though 

 somewliat deei)er than the corresponding segments. The 1st pair are scarcely 

 expanded distally, and are transversely truncated at the tip, whereas the 2 

 succeeding ones appear more rounded distally. The 4th pair, as usual, are 

 much broader than the others, and form beneath the posterior emargination 

 an angular corner. 



The epimeral plates of the metasome are normally developed, the 1st 

 pair being rather small and rounded, whereas the last 2 pairs are compara- 

 tively large, and acutely produced at the lateral corners. 



The urosome has the 2 anterior segments elevated dorsally, in a mannei- 

 similar to that in G. Grimmi, to narrow prominent tubercles, tipped, the 

 anterior with 4, the posterior with 2 spines. On the sides of the 1st seg- 

 ment no spines are present, but on the last segment, 2 small juxtaposed 

 denticles are found on each side, at the base of the telson. 



The eyes are very small, but distinctly reniform, having a rather deep 

 sinus anteriorly. 



The sujierior antennae are rather slender, though somewhat less elong- 

 ated than in G. Grimmi, not attaining half the length of the body. The 1st 

 joint of the peduncle is rather large, equalling in length the other 2 com- 

 bined. The flagellum does not ((uite attain to twice the length of the peduncle, 

 and is divided into numerous short articulations. The accessory appendage 

 is nearly twice as long as the last peduncular joint, and extremely narrow, 

 being composed of G articulations. 



The inferior antennae are somewhat shorter than the superior, but con- 

 sidei'ably more strongly built, and also more richly supplied with bristles. 

 Tludr structure is the usual one. 



The gnathoi)oda, at least in the male, are very unequally developed, 

 tlu! ])osterior ones (fig. 4) being much more powerful than the anterior 

 (fig. 3). The propodos of the former is fully twice as large as that of the 

 latter, and somewhat pyriform in shape, being considerably tumefied in its 

 proximal part, and tapering distally, with the palm rather oblique and de- 

 fined behind by a slight, spinous corner. 



*H3.-MaT. CTp. 284. 34 



