110 ART, 2. — H, MATSÜMOTO : 



Ophiophthahnus niicrohylax (Clark). 



Opldomitra microliylax : Clark, Bull. U. S. Nat. Mus., LXXV, 1911, 

 p. 184, fig. 84. 



Eastern Sea ; 103-152 fathoms (Clark). 



Ophientrema Verrill, 1899. 



Clark^^ says that his Opliiacantha leucostida " is almost 

 certainly entitled to be the type of a new genus, the large 

 amount of uncalcified skin and the peculiar condition of arm 

 spines and tentacle scales furnishing good generic characters." As 

 far as I can judge, the species in question belongs to Veeeill's 

 subgenus Ophientrema, being identical with Ophiacantha [Ophientrema) 

 scolopendrica Lyman, 1883. 



Though Ophientrema was established as a subgenus of 

 Ophiacantha, I am inclined to rank it as a distinct genus, because 

 the shape of the radial shields, the large basal tentacle pores, the 

 peculiar lower arm spines and tentacle scales, &e. are different 

 from those of the genuine Ophiacantha. This procedure would 

 naturally satisfy the need felt by Claek. 



Key to species of Ophientrema. 



^ — Disk covered with fine imbricating scales, and with minute, thorny, 



scattered tubercles euphylacteiim. 



^A. — Disk covered by a soft skin, scales being distinct only near the 

 radial shields, and Avith minute, scattered granules . . scolopendricum. 



Ophientreina eiipliylacteutn, 



Ophiacantha euphjladea : Clark, Bull. U. S. Nat. Mus., LXXY, 1911, 

 p. 225, fig. 105. 



1) Bull. U. S. Nat. Mus., LXXV, ISHl, p. 230. 



