560 MAJOR E. E. AUSTEN ON THE 



of lack of complete agreement among the ypecies mentioned or 

 described in the following pages, in respect of certain structural 

 details. Included among the latter are : — The degree of develop- 

 ment of the facial " beak " ; the shape of the terminal segment of 

 the maxillary palpus; the shape of the terminal division of the 

 third (compound) segment of the antenna in the female; and 

 the presence or absence of a distinct snbfemoral spine on tlie hind 

 legs. 



Although, by concentrating attention on one or other of these 

 characters and disregarding the remainder, it Avould perhaps be 

 possible in the case of certain species to select distinctions of 

 apparently generic value, yet in other forms intergradations 

 occur which make the drawing of a hard and fast line of demar- 

 cation impossible. Thus, to take only one of the characters 

 referred to : — Enderlein (/oc. cit. p. 99), writing of the terminal 

 division (called by him the tenth segment) of the female antenna, 

 says that this " in Pantophthalmus tapers gradually to a point, 

 but in Acanthomera and Rhaphiorhyuchus becomes but little 

 narrower towards the end, and then, just before the tip, is 

 suddenly pointed." This statement is certainly true if we com- 

 pare the antenna of the female in species such as Pantophthalmics 

 tahmdnus Thunb., or P. bellardii Bell, (both of which belong to 

 Pantophthalmus, sensu stricto) with that of the female of e. g. 

 Paidophthalvms {Acanthomera) chuni Enderl. IBut when we 

 examine the antenna in the female of PantophthalTnus ir'utiis 

 {Acanthomera jncta) Wied. — a species with a well-marked sub- 

 femoral spine, and the genotype of Acanthomera — we find that it 

 is intermediate between tlie two conditions. Moreover, in the 

 female of Pantophthalmus vittattis {Acantlioiaera viltata) Wied. — 

 a species assigned by Endei-lein himself [loc. cit. p. 107) to 

 Pantophthalmus — the terminal division of the anteiinais precisely 

 of the type regarded by Enderlein as characteristic of Acanthomera. 

 As regards the maxillary palpus, the tei-minal segment of this 

 structure is also subject to a certain amount of variation in shape 

 in <lillerent species. Although usually slender and cylindrical, 

 and, at least in the female sex, longer than the remainder of the 

 palpus, it is sometimes shorter and also stouter, albeit never 

 swollen in the manner characteristic of the terminal segment of 

 the palpus in Rhaphiorhynchus. 



That Enderlein is in error when he asserts {loc. cit. p. 100) that 

 in Pantophthalmus, sensu stricto, the facial beak is represented 

 merely by a "rounded tubercle-like swelling" is pointed out by 

 Hermann (Deutsche Ent. Zeitschr., Jahrg. 19'l6, p.48 (1916)), who 

 shows that in P. alienus Herm. the absence of a sid)femoral spine 

 on the hind legs is correlated with the presence of a "long, 

 pointed, tooth-like facial process." A further example of the 

 condition seen in P, alienus Herm. is afforded by the new species 

 described below as P. latest (cf. p. 566), in the male of which, at 

 any rate, while the fjicial beak, though small, is conspicuous and 

 sharp-pointed, the posterior femOra ai-e either without a spine 



