50 



THE CANADIAN ENTOMOLOGIST. 



Micraedes, Coq. 

 ; Isostoinyia, Coq. 



Mochlostyrax, D. &: K. 

 Sabethes, R.-D. 



SabetJioides, Theob. 

 VVyeomyia, Theob. 



Dendromyia, Theob. 



Limatus, Theob. 



Simondella, Laveran. 

 Phonioniyia, Theob, 

 Lesticocampa, D. & K. 

 Runchomyia, Theob. 

 Joblotia, Blanchard. 



Trichoprosopofi, Theob. 



A NEW SPECIES OF xMEGARHINUS. 



BY FREDERICK KNAB, WASHINGTON, D. C. 



A small lot of mosquitoes which were recently received from Dr. \V. 

 F. Thornton, of Bluefields, Nicaragua, contains a single specimen of a 

 Megarhinus, which represents a new species. It is related to the forms 

 with white-ringed tarsi, recently dealt with in a paper by Dr. Dyar and 

 myself (Smithonian Miscellaneous Collections, Quarterly Issue, xlviii, 

 241-258, 1906), but differs from all the known species in that the white 

 on the hind tarsi does not encircle them, but is upon the outer side only. 



Microscopic preparations show that the so-called second and third 

 segments of the male palpus are really one, being only apparently divided 

 by a false joint, a slight constriction accentuated by a difference in the 

 coloration of the scales. The male palpus is, therefore, only four-jointed, 

 consisting of a very short basal joint, a very long second joint (apparently 

 homologous with the third joint of the males of the Culicine and 

 Anopheline forms), a third shorter joint, and a fourth long and sabre-like. 

 In the female there is a fifth very minute terminal joint, hidden beneath 

 a dense vestiture of scales. What has been called the first abdominal 

 segment in previous descriptions is in reality the post-scutellum, which 

 overlaps the basal portion of the abdomen. In the following description, 

 for the sake of uniformity, the palpi are treated as in previous descriptions. 



Megarhinus hypoptes, new species. — -Male : Head behind the eyes 



velvety-black, the eyes broadly bordered with light metallic-blue, beneath 



and at the sides silvery. Antennae densely plumose : the toruli with silvery 



lustre ; second segment long and stout, longer than the three succeeding 



ones, somewhat compressed laterally, the heavy scahng of the crest 



condensed to a prominent iridescent blue patch on the anterior portion. 

 Palpi metallic-blue and purple, segments 2 to 4 pale lilac at the tip, second 

 and fourth segments nearly equal, the third longer, fifth twice as long as 

 the fourth. Prothoracic lobes deep metallic-blue. Mesothorax greenish- 

 black on the disk, with a few coppery scales intermixed ; the anterior and 



February, 1907 



