198 



lobes separated by a rather broad sinus, and terminating in an incurved 

 dentiform projection. Mandibles with the cutting edge coarsely dentate, 

 accessory lamella of the left mandible rather broad, securiform, with a finely 

 serrated edge. First pair of maxillae very large, basal lobe obcordate in form, 

 and edged with numerous ciliated setse, palp uniarticulate, not expanded distally, 

 and reaching about to the end of the masticatory lobe, its tip armed with 

 a few denticulated spines. Second pair of maxillse with the inner lobe 

 broadly oval, the outer elongated linear, and bearing on the tip a number 

 of slender spines, each terminating with a hatchet-shaped, uncinate dilatation. 

 Maxillipeds with the basal lobe of moderate size, and obtusely rounded at 

 the tip, masticatory lobe large and broad, slightly serrated on the inner 

 edge, palp very slender. Grnathopoda somewhat unequal, the anterior ones 

 being more robust than the posterior, with the propodos scarcely attenuated. 

 The two posterior pairs of pereiopoda not very dissimilar, basal joint in 

 both laminarly expanded. Last pair of uropoda with the rami subequal, 

 lanceolate and uniarticulate, their edges minutely denticulated. Telson trian- 

 gular, deeply cleft, unarmed. 



Remark*. In the restriction here adopted, this genus is chiefly 

 characterised by the two posterior pairs of pereiopoda being subsimilar in 

 shape, both having the basal joint laminarly dilated, as also by the somewhat 

 robust structure of the anterior gnathopoda. The genus comprises as yet 2 

 distinct species, which will be described in the sequel. 



1. Stegocephalus inflatus, Kroyer. 



(PI. 69). 



Stegocephalxs in flatus, Kroyer, Nat. Tklsskr. 1 R. Bd. 4, p. 150. 

 Syn: Stegocephalus ampulla, Boeck and others (but not Phipps). 



Body very robust and tumid, with the back broadly vaulted and 

 strongly deflexed anteriorly. Cephalon produced in front to a rather strong 

 deflexed rostrum, reaching to the end of the 1st peduncular joint of the 

 superior antennae, lateral corners somewhat projecting, and narrowly rounded 

 at the tip. First segment of mesosoine longer than the others, but shorter 

 than the 2 succeeding ones combined. Fourth pair of coxal plates very large, 

 nearly twice as deep as the corresponding segment, their breadth equalling 

 that of the 3 succeeding pairs combined, posterior expansion rather broad, arid 

 quite encompassing the succeeding pair inferiorly, distal edge forming posteri- 

 orly a strong curve. Last pair of epimeral plates of metasome produced to 

 a sharp corner, inferior edge coarsely serrated, posterior one smooth. Superior 

 antennae with the 1st joint of the peduncle nearly twice as large as the 



