MOSQUITOS OF THE I'ALAEARCTIC REGION. 285 



The presence of spiracular bristles, the close similarity in the male hypopygium, 

 and the basally situated siphon-tuft of the larva, are points which seem to indicate 

 some connection, distant no doubt, with Theobaldia, a connection which would 

 not be suspected on a superficial examination. 



The species of this genus often have very specialised habits, and these have 

 a restricted distribution. Two species have already been recorded from the 

 Palaearctic region ; what is probably a third exists in south-east Europe. 



1. Megarhinus christophi, Portch. 



Megarhinus christophi, Portchinsky, Horae Soc. Ent. Ross, xviii, p. 122 (1884). 



I do not know this species. According to Portchinsky's description it differs 

 from M. towadensis in having silvery transverse bands on each of the first six abdominal 

 segments and yellow lateral hairs on the sixth segment. 



Distnbution. — Amur {Portchinsky) . 



2. Megarhinus towadensis, Mats. 



Megarhina towadensis, Matsumura, Thousand Insects of Japan, Add, ii, p. 445 

 (1916). 



This is very much like the common Oriental M. regius (Tennent), but there are 

 differences, evidently of specific value. The only specimen I have seen is one sent 

 for determination from the Paris Museum by M. Seguy. This agrees with Mat- 

 sumura's description, except that the narrow white ring on the first joint of the 

 middle tarsus is close to but not at the base (the front legs are missing). The thorax 

 is much rubbed, but the remaining mesonotal scales are metallic emerald green, 

 quite unlike the dull scales of M. regius. The abdominal tuft is large and conspicuous, 

 the long hair on the sixth and seventh segments black, on the eighth segment orange. 

 The venter is mainly shining blue, but there are lateral yellow patches on 

 sternites two, three and six, and sublateral, elongate yellow triangles on sternites 

 four and five. 



Distribution. — Japan (Towada, Matsumura ; Kofou, L. Drouart de Lezey, 1906). 



3. Megarhinus sp. 



It is necessary to mention here a Megarhinus larva which was obtained near 

 Karasouli, Macedonia, by Capt. Waterston. 



The specimen was taken with a number of other larvae of different insects which 

 were thought to be preying on mosquito larvae. It was not identified until after 

 the collector's return to England, and no attempt was made at the time to rear it 

 or to obtain others. It differs only in minute characters from the larvae of the 

 African M. brevipalpis, the Oriental M. regius. and the North American M. rutilus, 

 and it is therefore impossible to say whether it belongs to one of these species, or to 

 some other, perhaps undescribed, form. 



Genus Theobaldia, Neveu-Lemaire. 

 The two characters on which most writers have based their conception of this 

 genus — the spotted wings and the position of the cross-veins in a straight line or 

 nearly so — are both worthless for purposes of definition. In T. longiareolata and 

 in the subgenus CuliceUa the cross- veins are well separated ; while, on the other hand, 

 in Lutzia vorax and occasionally in some other species {e.g., Culex tipuliformis, 

 Aedes rusticus) they are practically in a straight line. The female palpal character 

 on which Neveu-Lemaire founded the genus is of even less value. In one point, 

 however, the adults do seem to be sharply distinguished from most other genera of 

 the tribe Culicini. This is in the possession, immediately in front of the prothoracic 

 (4183) X 



