160 
Ophiuroid larvæ, nothing corresponding has been observed in the 
Asteroid larvæ. J. F. Gem miil in his memoir on the development 
of Asterias rubens *) records the existence of a sub-epidermal net- 
work of nerve fibres and of a set of neuro-muscular cells (also 
Fig. 8. Ophiuroid larva, with the two nervous bands (n.). Diagrammatic. 
observed in the larva of Porania pulvillus). But anything corres¬ 
ponding to the larval nervous system lying in the epidermis in 
the circumoral region of Ophiurid and Holothurioid larvæ and — 
at least — in the larva of Echinocyamus pusilliis among Echinoid 
larvæ is unknown and would appear not to exist in Asteroid larvæ. 
*) James F. Gemmil. The development and certain points in the adult 
structure of the Starfish Asterias rubens L. Philos. Transactions. Ser. B 
Vol. 205. 1914. p. 264. 
19-1-1920. 
