282 Mr. i\[. Burr's Ohscrvations on 



Diplatys viacrocejjhala, Pal. Beau v., aud I), r affray i, Borm. 



These two species are invariably confused in collections, 

 and I doubt whether de Bormans himself accurately 

 appreciated the difference between them ; at all events, in 

 his monograph in Tierreich he attempted to discriminate 

 between them by their colours alone, an entirely deceptive 

 method, that is bound to make confusion worse confounded. 

 The colouring of the two species is the same and varies 

 in the same manner. The difficulty is complicated by the 

 apparent dimorphism of the males. The typical male 

 of both species has the last abdominal segment large 

 and tumid, and the forceps stout, strongly flattened, and 

 dilated near the base, and then suddenly attenuated, and 

 incurved ; in a male in my collection (ex. coll. de Bormans) 

 from Stanley Pool, Congo, the forceps recall those of typical 

 Forjiaula ; the other, and perhaps commoner form, resembles 

 the female, and these are to be mistaken for hermaphrodites. 

 In the synoptical table I have endeavoured to set forth 

 the distinctions as they appear to me. 



Di2Jlaf't/s gerstcvxkcri, Dohrn. 



Much doubt has existed as to the relations between 

 Nannopygia gerst.vckeri and Diplatys longisetosa ; de 

 Bormans actually retained Dohrn's genus, but it coincides 

 without any doubt with Serville's earlier erection. 



At the time of Mr. Green's paper on D. longisetosa (Tr. 

 Ent. Soc, 1898, p. 881) I was unfamiliar with Dohrn's 

 species, and so described Mr. Green's insect under West- 

 wood's name (1. c, p. 388), but in a later paper (The 

 Earwigs of Ceylon, Journ. Bombay N. H. Soc, 1901, 

 November, p. 75) I have united the two species. I will 

 again quote a letter from Dr. Kuhlgatz of the Berlin 

 Museum, who kindly examined Dohrn's type for me : " D. 

 longisetosa is very closely allied to this species (i.e. N. gcr- 

 sta^ckeri), but not actually identical with it. Nannopygia 

 gerstxclceri is entirely bronze-coloured with black eyes ; in 

 Diplatys longisetosa the head is black ; the forceps increase 

 a little more in thickness from the apex to the base than 

 in Nannopygia gerstxekeri ; the elytra of the latter are uni- 

 form in colour and broader than in D.longisctosa,m which the 

 two posterior thirds of the elytra have a long blackish 

 shadowy streak (at least in the two specimens in the 



