NOTES UPON THE GENERIC TERMS 

 CASSIDARIA AND ONISCIA. 



By EDGAR A. SMITH, F.Z.S., 



British Museum (Zoological Depaytmcnt), London. 



Both of these genera for many years found general acceptance, 

 until the appearance of the Manuals by Philippi and the Messrs. 

 H. and A. Adams. Tryon, who had an aversion to upsetting 

 what he considered established names, employs both of them, 

 and they likewise appear in \\'oodward's Manual. On the other 

 hand, they are rejected by the Messrs. Adams, Galcodca and 

 Morum being respectively substituted. Philippi rejects Cassidavia 

 in favour of Movio, and employs Oniscia ; and in the latest Manual 

 by Fischer, the same course is adopted. Seeing this great 

 divergence of opinions, I thought it would be useful to place on 

 record the result of a further independent investigation. I will 

 therefore proceed to discuss these two genera separately, com- 

 mencing with Cassidavia. 



Cassidaria. 



Herrmannsen, Philippi, Fischer, Watson and Chenu give 

 the date of Lamarck's Cassidavia as 1812. This is not correct, 

 for, although the French term " Cassidaire '"' appeared in that 

 year, but w'ithout one word of description, it was not until 1816 

 that the Latinized form, Cassidaria, was employed. In the ex- 

 planation of plate 405 of the Encyclopedic Methodique, which 

 was the work of Lamarck himself, and was published in 181 6, 

 the term Cassidavia is there applied to the well-known Cassidavia 

 tyvvhena. There is, however, no generic description whatever, 

 and, apparently, the genus was not properly characterized until 

 1822, in the seventh volume of the Syst. xAnim. sans Vert., 

 p. 214. 



However, if 18 12 were admissible as the date of this genus, 

 it could not be retained, as two other properly characterised 



I Extrait du Cours de Zool., 1812, p. 119. 



