BY THE REV. T. BLACKBURN. 541 



it from Melolontha, when Boisduval re-described it as Sericesthis 

 geminata. Surely then the name Sericesthis must stand. 



According to M. Blanchard (whose statement, apparently on 

 the authority of its author, is reproduced by Dr. Burmeister and 

 M. Lacordaire), a species which Boisduval described under a new 

 generic name, — Cotidia australis, — is in realitv identical with 

 Sericesthis geminata, Boisd., — but in spite of M. Blanchard's 

 having apparently seen the original type T do not think this 

 synonymy can be accepted, — for although Boisduval's description 

 of Cotidia australis is insufficient for the identification of that 

 insect, the description is absolutely inconsistent with such 

 synonymy ; Boisduval's description contains the phrase " subtus 

 pilis fulvis hirsuta," and since nothing is said in any of the 

 descriptions of Sericesthis about the underside being hirsute 

 (although in several of them the underside is referred to), it seems 

 fairly certain that Boisduval's Cotidia australis is really hirsute 

 on the undersurface (as in Colpochila) and not merely furnished 

 with some thin inconspicuously dispersed pilosity (as in Scitala 

 pruinosa, Dalm. &c.), and it would be easier to believe that the 

 original type had been confused with^some other specimen than 

 that the genus Cotidia was founded upon a species not distinguish- 

 able by the greater pilosity of its undersurface from the ordinary 

 types of Sericesthis. Of course Boisduval's phrase if applied to a 

 Sericesthis (say S. pruinosa) would not be more than an exaggera- 

 tion of the i-eal condition of the undersurface ; but the point is 

 that Boisduval's descriptions of Cotidia and Sericesthis are irrecon- 

 cilable with any other theory than that the hirsuteness of the 

 undersurface was the distinctive character of Cotidia. One other 

 character capable of having been thought generic is attributed to 

 Cotidia atistralis, viz., " thorace globuloso convexo "; but as in no 

 description is the prothorax of Sericesthis alluded to at all by 

 Boisduval this is not likely to be the character on which that 

 author founded Cotidia ; and finally, — if it ?/;erethe character that 

 induced Boisduval to distinguish australis generically from his 

 Sericsthis geminata, &c., it would be equally effective with the 

 previously mentioned character in proving that Cotidia australis 



