389 

 Gren. 1. Syrrhoe, Goes, 1865. 



Body comparatively slender, with ratber thin integuments. Cephalon 

 strongly vaulted in front, and produced to a sharp rostrum curving down 

 between tlie bases of the superior antennae. Coxal plates comparatively small, 

 3r(l pair much the largest, and greatly expanded in their outer part; 4th pair 

 very poorly developed. Posterior edge of the segments of metasome more 

 or less distinctly serrated. Ej'es completely coalescent, and placed within the 

 dorsal part of tlie cephalon, as in the (EdiceridfB. Antennse comparatively 

 slender, the inferior ones in male greatly elongated. Anterior lip moderately 

 Iiroad, and scarcely insinuated at the tip; posterior lip with the lateral 

 lobes greatly expanded. Mandibles short and stout, with the cutting edge 

 distinctly dentated, and the molar expansion of normal structure, palp slender, 

 with the last joint very small, and provided with long curved setae. First 

 pair of maxillce with the palp well developed, masticatory lobe transversely 

 truncated at the tip, and armed with strong denticulated spines, basal lobe 

 of moderate size, and edged with several plumose setae. Second pair of max- 

 illae comparatively small, with the lobes short and subequal. Maxillipeds not 

 very large, masticatory lobes of moderate size, and armed along the inner 

 edge with curved spines, assuming at the tip successively the character of 

 strong setae, palp comparatively short and stout, with the 3rd joint expanded 

 distally, and the terminal one unguiform. (xnathopoda very slender and feeble 

 in structure, the posterior ones more elongated than the anterior, propodos in 

 both distinctly subclieliform, with the palm transverse, and armed with a single, 

 very strong, denticulated spine, which forms, as it were, a kind of thumb 

 against which the dactylus is allowed to impinge. The 2 anterior pairs of 

 pereiopoda extremely slender, though consideralil}' shorter than the 3 posterior 

 pairs, which rapidly increase in length, and iiave the basal joint considerably 

 expanded and more or less strongly serrated along the posterior edge. The 

 2 anterior pairs of uropoda subequal in structure, with both rami narrow 

 linear in form, tlie oi^ter being much shorter than the inner; last pair with 

 tlic rami less unequal and narrowly lanceolate in shape, the outer with a 

 small terminal joint. Telson more or less elongated and deeply cleft. 



BeniarJcs. — The present genus, which maj' be considered as the type 

 of the family Syrrlwidcc, was established by Goes in the year 1865, to include 

 2 species, one of which, however, had been described by Prof. Lilljeborg at a 

 somewliat earlier date as the type of a separate genus, Tiron. Among the 

 several characteristics distinguishing the present genus from the succeeding 

 ones, may be named the comparatively .slender form of the body, the large 

 confluent eyes, and the very peculiar form of the 3rd pair of coxal plates. 



.'iO — Crustacea. 



