308 ART. 2.— H. MATSÜMOTO: 



Arms moderately long, stout, cylindrical ; stoutest at the base, 

 horizontally flexible. Arm plates all well developed. Numerous 

 arm spines, short or moderately long, lying flat on the arm or 

 erect. One or two tentacle scales to each pore ; when there are 

 two, the abradial scale overlaps the base of the lowest arm spine. 



This family includes sixteen genera, which may be grouped 

 into two subfamihes as follows. 



Subfamily 1. Ophiarachnînœ Matsumoto, 1915. — Arm spines 

 not very short, erect. 



I. Oral shields entirely covered with granules ; arm plates 

 usually concentrically striated ; arm spines hyaline. 

 Ophiurocœns Matsumoto, 1915. 

 Ophiurodon Matsumoto, 1915. 



II. Oral shields naked ; arm plates not concentrically striated ; 

 arm spines opaque. 



Ophiurochceta Matsumoto, 1915. 

 OpMarachna Müllee t^- Tkoschel, 1842. 

 Subfamily 2. Ophiodermatinœ Matsumoto, 1915. — Arm spines 

 very short, lying flat on the arm. 



A. Single tentacle scale to each pore. 

 I. Oral shields entirely covered with granules. 



Ophioconis LiJTKEN, 1869 { = Ophiocormus Clakk, 

 1915).^^ 



1) I can not find in Clark's description and figures any tangible character, by which his 

 OpJiioconmcs is distinguished from the genuine OpTdoconis. The bhmt tip of the arms and the 

 very short and apprcssed arm spines of his Ophiocormus are not at all Ophiocanthine but 

 perfectly Ophiodermatine. Clakk's unique specimen, on -which his genias is based, is certainly 

 very young, measriring only 3 mm. across the disk and 6 mm. in the arm length. So that, 

 all the " notable " characters are merely what may be expected in such a young specimen. 

 In my opinion, Ophiocormus is a genuine Ophioconis, if indeed it is not a yoiing stage of 

 CrifftoixKa. 



