585 



female of the form upon wliicli he at first founded his genus FJeoncxes, I 

 have felt justified in restricting the present genus to the 2nd species referred 

 by him to the genus Sunampliithoe , viz., S. conformata. A closer examination 

 of this form has indeed shown it to be generically distinct both from tlie 

 genus Amphithoii and Pleonexes. The chief distinguishing characteristics refer 

 to the structure of the gnathopoda, and especially the remarkable transforma- 

 tion of the posterior ones in the male. Moreover, the absolute want of 

 mandibular palps is a very prominent characteristic, apparently of generic 

 value. In the structure of the pereiopoda and caudal appendages, it agrees 

 more closely with the genus Amphitho'r than with Pleonexes. Of the several exotic 

 species of Amphitlioe described by different authors, at least 3 species may 

 most probably be referred to this genus, viz., A. pclagica M.-Edw., A. cJiihiisis 

 Nicoli, and A. orientalis Dana. To the fauna of Norway belongs but a single 

 species, to be described below. 



3. Sunamphithoe conformata, Sp. Bate. 



(PI. 208). 



Sunamphithoe conformata, Sp. Bate, Catal. Ampli. Brit. Mas., p. 261, PI. XLIII, fig. 6. 



Syu ; Ampliithoe grandiiiiaua, Boeck. 



Body moderately slender, smooth, with evenly rounded back. Cephalon 

 with the lateral corners broadly rounded, and defined from the postantennal 

 ones by a slight sinus. Anterior pairs of coxal plates somewhat deeper than 

 the corresponding segments, and having each a series of slender bristles on 

 the distal edge; 1st pair scarcely expanded distally, 5th pair with the anterior 

 lobe very large and broad, being obtusely truncated at the tip. Last pair 

 of epimeral plates of metasome nearly rectangular. Eyes small, rounded, 

 and placed at some distance from the lateral corners of the cephalon, pigment 

 dark red. Superior antennae very slender, considerably exceeding half the 

 length of the body, 1st joint of the peduncle much the largest, 3rd joint very 

 small, flagellum nearly 3 times as long as the peduncle, and composed of 

 numerous short setiferous articulations. Inferior antennae but little more 

 than half as long as the superior, last joint ot the peduncle shorter than 

 the penultimate, flagellum not attaining the length of those joints combined. 

 Anterior gnathopoda of same structure in the two sexes, being rather slender, 

 with the carpus slightly expanded, propodos rather narrow and oblong in 

 form, palm short transverse, dactylus longer than the palm. Posterior 

 gnathopoda in female but little stronger than the anterior, and of a very 



