70 ART. 2. — H. MATSUMOTO : 



plementaiy plates. Teeth, dental papillae and oral papillae very 

 few in number. 



Arms covered by a pavement of flattened, polygonal granules, 

 and distinctly annulated by double rows of compound hooks, of 

 which the terminal booklet is smaller than the accessory one. 

 Ventral side of arms covered by a naked skin, through which the 

 ventral and lateral arm plates are visible. Two small, peg-like 

 arm spines occur on the second and outer lateral arm plates. 



Colour in alcohol white. 



The smaller one of the two specimens is only 1 mm. across 

 the disk and has the arms divided only once. The disk is entirely 

 covered with the primaries and the radial shields, secondary plates 

 being absent. The arms are not yet annulated by the double 

 rows of compound hooks, but there are from three to five second- 

 ary plates in place of each dorsal arm plates, so that the dorsal 

 view of the arms reminds us of that of Hemieuryale. 



Key to Japanese species of Gorgonocephalus, 



A — Arms composed of short shafts ; arm spines almost as long as the 



corresponding arm joint. 

 a — Teetli and papillae, as weU as arm spines, very acute ; internal 



structm'e of the first type tuherosus. 



aa — Teeth and papillae, as weU as arm spines, blunt; internal structure 



of the second type caryi. 



AA — Arms composed of long shafts; arm spines shorter than half the 



corresponding arm joint ; internal structure of the third type 



dolicliodadylus. 



Gorgonocephalus ttiberosus Döderlein. 

 Gorgonocephalus tiiberosus : Döderlein, Zool. Anz., XXV, 1902, p. 



