330 AKT. 2.' — H. MATSUMOTO : 



Lat. 5° 41' S., long. 134^ 4' E. ; 800 fathoms (Lyman). Gulf of 

 Panama ; 322-546 fathoms (Lütken & Moetensen). 



The largest of my specimens is 31 mm. in the disk diameter, 

 400 mm. in the arm length, and 4 mm. in the arm width ; and 

 the smallest one 8 mm. in the disk diameter, 52 mm. in the arm 

 length, and 0.8 mm. in the arm width. This species is very 

 variable, and has been remarked upon by Claek. The adorai 

 shields are sometimes very feeble, but often very w^ell developed, 

 especially in the younger specimens, so as to lie between the oral 

 shields and the first lateral arm plates. Therefore, Kœhlek's 

 subdivision of this genus according as the oral shields are separated 

 or not from the first lateral arm plates, has no meaning at least 

 for the present species. Often, more or less prominent accessory 

 oral shields occur in some of the interradii. This is another fact 

 showing that the present genus is related to Ophiarachna. 



I consider 0. carinatus Lütken et Moetensen to be a synonym 

 of this species, because specimens of the latter of corresponding 

 size agree almost perfectly with the description and figures of the 

 former. The figures here given, together with those of medium- 

 sized specimens by Lütken & Moetensen will give a fair idea of 

 the variability of this species. 



Ophioplax lamellosa Matsumoto. 



Oj^liioplxxx lamellosa : Matsumoto, Proc. Acad. Nat. 8ci. Philadelphia, 

 1915, p. 88. 



One specimen ; off" Kôtsu-jima, Sagami Sea. 



Diameter of disk 4.5 mm. Length of arms 35 mm. Width 

 of arms at base 0.8 mm. 



Disk flat, thin, pentagonal or rather five-lobed, with indented 

 interbrachial borders, covered with fine, imbricating scales, among 



