420 



Mr. W. K. Fislier on new 



C-. Disk-plates small, bearinpr one to several 



small spinelets ; on the ray there is 

 only one lateral or marginal spiue 

 corresponding to the variably spaced 

 inferomargiual plates, never a vertical 

 comb of conspicuous lateral spines. 

 (P. First a7id second adambulacral plates 

 as "svell as the upper part of tlie 

 second and third ambulacral plates 

 united by syzygy (nou-muscular 

 symphysis). 

 e^. Abactinal skeleton of rays in the 

 form of independent, spaced arches 

 or costfe composed of elongate, 

 more or less compressed, over- 

 lapping plates, projecting well 



Fi-. 1. 



Fig. 2. 



Fig. 1, — Brissimja trachydisca. Oral angle from actinal side. 

 Fig. 2. — Ditto. Lateral view of iuterbrachium, rays removed. 



lu all figures : a, first adambulacral plate ; am, ambulacral plate ; 

 /, iuterradial plate; vi, marginal plate; o, moutu-plate. 



above the level of the intervening 

 integument and bearing small 

 spinelets ; intercostal integument 

 nut fortitied by thin, immersed, 

 spineless, fenestrated plates. 

 f^. Gonads numerous, in a series 

 along either side of each ray ; 

 the iuterradial (first) pair i»f 

 adambulacral plates is joined by 

 the interradial faces, and above 

 them is a united pair of first 

 marginal plates — four in all 

 (tigs. 1 and 2). 

 (j^. Snbambulacral spines of proxi- 

 mal adambulacral plates 



