1906.] MISS G. RICARDO OX A XEW SPECIES OF FLY. 97 



in which he describes two fully adult living specimens. He says : — 

 " The two living specimens, which are now under my inspection, 

 show that my former description was taken from very young 

 specimens of about half their full size, and that this northern 

 species comes much nearer in size to the southern species 

 [J)olichotis patagonica) than I was formerly led to suppose." 



It is now quite clear from specimens collected by Mr. P. O. 

 Simons in 1901, and described by Mr. Oldfield Thomas, that the 

 living specimens described by Dr. Burmeister in his second pajjer 

 were Dolichotis magellanicus centricola and not Dolichotis salinicola, 

 and that those described in his first paper were full-grown or 

 nearly full-grown specimens of the dwarf species Dolichotis salini- 

 cola, which I have now alive in my possession. 



Both these species occur in the saiiae region near Santiago del 

 Estero in Northern Ai"gentina, so that confusion was easy. 



The common Patagonian Cavy is conspicuous for a broad dark 

 band above the white rump-patch. This black band is wanting 

 in Dolichotis salinicola and also in the larger Dolichotis magellanicus 

 centricola. 



EXPLANATION OF PLATE IV. 

 Dolichotis saliyiicola. 



3. Description of a new Fly of the Family Tahanidce. 

 By Gertkude Ricardo. 



[Received December 7, 1905.] 



Melissomorpha, gen. nov. 



Formed for a fly from Rungaroom, Sikhim, in the British 

 Museum Collection, which closely mimics Apis dorsata F., an 

 Indian species. 



The genus belongs to the Pangonince division of the family 

 7'abanidcp, which is distinguished by the hind tibise being furnished 

 with spines, ocelli usually present, and the third joint of the 

 antennae consisting of eight divisions, with no tooth. 



This genus will come under ISTo. 9 in my table of genera of 

 Pangoni7ice in the Ann. Mag. JSTat. Hist. (7) v. p. 98 (1900) : 

 " Proboscis scai-cely extending beyond the palpi," which dis- 

 tinguished Apatolestes, a North American genus. The two genera 

 may now be divided thus: — 



Having the appearance of a Bee {A2ns). All the tibise wide 

 and flattened Melissomorpha, gen. no.v. 



Not having the appearance of a Bee. The tihias. not wide and 

 flattened Apatolestes W}]\. 



Melissomorpha, gen. nov. 



Generic description. — Antennfe eight-jointed, ocelli present, 

 Proc. Zool. Soc— 1906. Yol. I. No. YII. 7 



