338 



lOO fathoms. Mr. Schneider found it sub.seqiiently also in the neighbourhood 

 of Tromsa; but farther south it has not yet been met with. 

 Distribution. — Greenland (Hansen). 



Gen. 12. AcerOS, Boeck, 1860. 



Body comparatively slender, with rather small coxal plates, the Ist 

 pair of which are considerably expanded distally. Cephalon truncated in 

 front, without any distinct rostral projection. Eyes inconspicuous, and replaced 

 by 2 small distant patches of pigment. Antennae slender, the superior ones 

 much the longer, and having the peduncle greatly prolonged, whereas the 

 flagellum is extremely small. Oral parts resembling those in the genus 

 HaJiinnlon' the mandibles being, however, comparatively still more strongly 

 built, and the palp of the maxillipeds larger. Gnathopoda rather slender 

 and subsimilar in structure, carpus in both pairs elongated, and produced 

 inferiorly to a narrow setous lobe, propodos not very strong, subcheliform. 

 The 2 anterior pairs of pereiopoda somewhat larger than the 2 succeeding 

 ones, which latter are nearly equal both as to size and structure. Last pair 

 of pereiopoda of the usual slender and elongated form. Uropoda and telson 

 likewise of normal appearance. 



EemarJcs. — The present genus was established by Boeck as early as 

 in the year 1860, to include the form briefly described by my late father as 

 Leucotho'e phyllonyx, and subsequently recorded by Bruzelius under the name 

 of (Ediceros ohtusus. The generic denomination refers to the absolute want 

 of any frontal projection, whereby this genus, indeed, stands quite alone 

 among the (Ediceridee. In the structure of the oral parts and that of the 

 gnathopoda, it seems to resemble the genus Halimedon, from which however it 

 differs in the structure of the antennae and pereiopoda. Besides the typical 

 species described below, the (Ediceros Novee-Zealandice of Dana would seem 

 to belong to this genus. 



32. Aceros phyllonyx (M. Sars). 



(PI. liy, PI. 120 tig. 1). 



Letieothot phyllonyx, M. Sars. Christ. Vid. Selsk. Forliandl. 1858, p. 148. 



Syn. ; O^diceros obtusus, Bruzelius. 



Body rather slender and elongated, but considerably tumefied in its 

 anterior part, with all the segments sharply defined. Cephalon about the 



