77 



THE GEOGRAPHICAL DISTRIBUTION AND SYNONYMY OP THE 



DASYTID-BEETLE AGANTHOCNEMUS NIGRICANS Hope 



{ = C HIATUS Peeris). 



BY G. C. CnAMPIOX, r.z.s. 



Bourgeois (Bull. Soc. Ent. Fr. 1904, pp. 25, 26), in a paper entitled 

 " Sur le cosmopolitisme de V Acanthocnemus cUiatus Ferris, Coleoptere 

 de la tribu des Dasytides," gives a detailed account of the extraordinary 

 distribution of this beetle and of its formid- 

 able S3"onym3\ The species, he says, has been 

 described under six different names, and re- 

 ferred to three different genera. Nevertheless, 

 tvro specific names have still to be added, 

 nigricans and fiiscipennis Hope, one of which, 

 nigricans, must replace that of ciliafus Ferris, 

 it having 21 years' priority. The types of 

 Hope's insects, both of which were referred 

 by him to the genus Dasytes, and both from 

 Adelaide, S. Australia, have been lent me by 

 Prof. Poulton, and they agree perfectly -with 

 an example of Acantlwcnemus ciliafits from 

 Erbalunga, Corsica, kindly communicated by 

 Lt.-Col. J. St. Claire Deville. Mr. A. M. Lea, 

 in re-describing these Australian insects in 

 1909, is the onl}' author who has noticed one 

 of the most important characters of the genus, 

 viz. the presence of very deep, almost circular 

 foveae (these having a silvery appearance in 

 certain lights) on the propleura, about wdiieh 

 the French and German writers say nothing, 

 their diagnoses having doubtless been drawn up from carded specimens. 

 A. nigricans has the general appearance of a Trogositid or Ci-ypto- 

 phagid, and the hairy body and ciliate elytral margins of certain 

 Dasytids, amongst which the genus seems best placed.* The insect 

 has been described by Lea, as Avell as by other authors, and it is onl}' 

 necessary to say that it is of a flattened, subcylindrical shape, blackish 

 or fuscous in colour, with the antennae and legs more or less ferruginous ; 

 the numerous specimens before me measure from 4-5| mm. in length 

 and l|-2 mm. in width. The characters of the genus given below were 

 taken from Australian and Ehodesian examples before the descriptions 



* The genns Aniiioon Goi-Ti. (1SS6), type A. eribripenne, from Panama, described *s a Melyrid. is a 

 Trogositid allied to Dioiduluhus Solier. 



Acanthocne^nus vigricans 

 Hope, c? , X 9, the long 

 hairs on the dorsal sur- 

 face omitted; the lower 

 fig-ure shows the pro- 

 sternal foveae^ 



