98 



PAXA^riC DEEP SEA ECHES'I. 



still showing the cellular structure of the outer part of the circle. The 

 miliaries and secondaries also show this cellular structure. (PI. 46, 

 figs. 0-7). 



I have given a number of figures (Pis. 44 ; 45, figs. 1-^J) showing 

 the first formed auricular knobs (Pi. 45, fig. 1), Fig. 136, still well sepa- 



rated, with two ambulacral plates passed over onto the actinal system ; 

 next a somewhat older stage (PI. 45. fig. 2), in which the arch of the 

 auricles has become closed, Figs. 13"; 138, with five ambulacral plates 

 beyond the auricles ; and still older stages (PI. 45, figs. 3-d) showing the 

 flow of the ambulacral plates. Figs. 139, 140, under the arch of the auricle, 



69 mm. 



Fig. 1.%. Phobmosom.v nispiDuif. 



lo7 HUB. 



Fig. 140. Phobmosoma hispidum- 



by the breaking up of the ambulacral plates into a median and exterior 

 part, the median carrying the pores beyond the auricle ; the outer part 

 left behind is crowded against the base of the auricles (Pis. 44, fig. S; 

 45, figs. 5, 6). The suture of one of these plates can be seen at the base 



