204 



completely encompassing the 2 succeeding pairs inferiorly. Last pair of 

 epimeral plates siibtriincated at the lateral corners. Eyes wanting. Antennae 

 nearly as in Stegocephalw?, subequal in length. Epistome projecting in front 

 as a rounded compressed lobe. Anterior lip but very slightly incised at the 

 tip; posterior lip narrower than in the preceding genera. Mandibles less 

 strong, with the cutting edge narrower, and less coarsely dentate. First 

 l)air of maxillae with the basal lobe ratlier large, but narrower than in Skgo- 

 ccphulus, and setous only in its outer part, palp extremely small, not 

 reaching to the end of the masticatory lobe, but distinctly biartieulate. 

 Second pair of maxillae very large, inner lobe considerably prolonged, 

 and somewhat expanded distally, outer lobe narrow linear, and wide apart, 

 articulated to a kind of peduncle originating from the basal part, apical spines 

 very slender and elongated, each terminating with a hooked bidentate expan- 

 sion. Maxillipeds with the basal lobe rather narrow, and obliquely truncated 

 at the tip, masticatory lobe large, reaching beyond the antepenultimate joint 

 of the palp, tlie latter joint produced at the end interiorly, to a digitiform 

 projection. Anterior gnathopoda somewhat stronger than the posterior, but 

 otherwise of much the same structure. Anterior pairs of pereiopoda very 

 powerful, with strongly curved, hook-like dactylus. Basal joint of the 

 penultimate pairs of pereiopoda narrow linear, that of last ])air laminarly 

 dilated. Uropoda and telson nearly as in Sfegoccphahidi's-. 



Remarks. — The present new genus is founded upon the form previously 

 described by the author, as Stegocephalm (jibboms. On a closer anatomical 

 examination, 1 have found this form to differ from the gemis Stci/occjilialns, 

 so markedly in several essential points, especially in the structure of the 

 oral parts, as more properly to be regarded as the type of a separate genus. 

 ■Besides the sjjecies described below, the Stegocephalns Kensleri of Stuxberg 

 (=^ Cancer ampulla Phippa) most probably belongs to tlie same genus. 



5. Aspidopleurus gibbosus, G. 0. Sars. 



(PI. 71, fig. 1). 

 Stcyoceplialus gibbosus, G. O. Sars, Oversigt af Norges Crustaceer, I, p. 85, PI. 3, flg. 7. 



Body somewhat slender, as compared with the other forms of this 

 family, back evenly curved and less abruptly deflexed in front. Cephalon 

 without any distinct rostral projection, latex'al corners scarcely projecting, 

 and nearly rectangular. First segment of mesosome but little longer than 

 the succeeding ones. Anterior pairs of coxal plates nearly twice as deep as 

 the body. Fourth pair fully twice as broad as the 3 preceding pairs com- 



