158 Prof. E. Forbes on Fossil Jnvertebrata from Southern India. 



ECHINODERMATA, 



Ophiurida. 



Genus Ophiura, Lamarck. 

 1. Ophiura? Cunliffei, sp. nov. PL XIX. fig. 8. 



Part of the disc and arms of a very distinct species, apparently belonging to the 

 typical genus Ophiura, and evidently allied to the Ophiura serrata of Romer, a 

 species found in the white chalk of Germany and of England. The plates of the 

 disc in the Indian fossil are larger than in any known species of the genus. 

 The disc-shields at the bases of the rays are broadly oblong and somewhat trian- 

 gular. The scales of the centre of the arms are small and angular ; the lateral 

 scales are very large and oblong. The spines are not preserved, but were probably 

 short and obtuse. The figure represents the specimen of the natural size. It was 

 found by Mr. Cunliffe at Verdachellum. 



Echinidce. 



The greater part of the specimens of Urchins in this collection were presented 

 by Mr. Cunliffe through Mr. Egerton. Not having been kept so carefully distinct 

 as the shells were, and all the specimens being free from rock, their locality, 

 whether from Pondicherry or Verdachellum, has not been marked. No specimens 

 of Echinidse are contained in the Trinchinopoly collection. 



Genus Holaster, Agassiz, 



Of this genus of Spatangacea there is a single species in the Pondicherry col- 

 lection. The genus Holaster was established by Agassiz for a group of Urchins 

 diflfering from Spatangus in the arrangement of the latero-dorsal ambulacra, which 

 in the former are radiate and not petaloid, and never placed in depressions. I 

 have for some time been inclined to dispute the propriety of the separation from 

 Spatangus of the species presenting these characters, dreading the tendency of 

 many distinguished living naturalists to extreme multiplication of generic groups. 

 Such a practice is unsafe, even in the hands of an Agassiz, and highly dangerous 

 when indulged in by those whose studies have been confined to limited depart- 

 ments of natural history. If carried too far, it will assuredly lead to much con- 

 fusion, since, when every alliance of a few species presenting unimportant charac- 

 ters in common is elevated to generic rank and endowed with a generic appellation, 

 the natural-history language by means of which general views can be expressed, 



