MARINE FAUXA OF ZANZIBAR,. 



321 



1904.] 



others, the posterior left ci-escentic plate lies alongside and 

 approximates to the size and shape of the great dental. The 

 numbers of the teeth are fairly large, they being especially small 

 and numerous on the crescentic plates. The following formula- 

 give their variation : — 



The asymmetry of the gi'eat dentals exists even when the 

 numbers of the teeth they bear ave the same, as was the case in 

 the specimen from which text-fig. 63 was prepared. The lowei' 

 jaws are almost entirely calcareous in composition and their end- 

 plates are indented. 



Text-fig'. 63. 



Upper jaws of a full-grown specimen of E. iudica. 

 Left anterior plates moved upwards from the natural position. 



The feet are comparatively long and slender with long set*, 

 and are well separated fi'om each othei-. The dorsal and ventral 

 cirri are well developed, but not annulated. Lai-ge gills covei- 



Proc. Zool. Soc— 1904, Yol. I. No. XXI. 21 



