150 Mr. R Smith on some new Genera and Species 



with fuscous and black pubescence ; the metathorax has a triangular 

 smooth shining space behind ; the wings subhyaline, their nervures 

 blackish-brown. The abdomen of a deep flesh-coloured red ; the basal 

 segment fringed with sooty-black pubescence ; the two apical segments 

 thinly covered with black hairs ; the segments beneath fringed with 

 black hairs. 

 Hab. St. Domingo. In the Collection of the British Museum. 



2. MegaciHssa eximxa. 



M. capite thoraceque nigrifl ; abdomine nigro-ameo ; thorace abdominisque 

 basi pube brevi fulva dense vestitis ; alis subhyalinis, venis fen-ugineis. 

 Female. Length 9 lines. Head and thorax black, the latter densely 

 clothed with short downy fulvous pubescence, which is palest on the 

 sides and beneath. The vertex fringed with fuscous pubescence ; a tuft 

 of the same colour occupies the space between the ocelli ; there is also 

 a similar tuft at the insertion of the antenna? ; the cheeks covered with 

 short downy white pubescence ; a line of the same colour runs round 

 the base of the clypeus and along the inner margin of the eyes ; the 

 clypeus rufo-fuscous ; the flagellimi, except the two basal joints, rufo- 

 fulvous beneath. The wings subhyaline, faintly clouded at their apex ; 

 the nervures ferruginous, the costa black ; the legs ferruginous, with a 

 dense fulvous pubescence, the intermediate and posterior tibia? fuscous 

 outside. Abdomen nigro-seneous, with a dense short fulvous pubes- 

 cence at the base ; the apical margins of the second and two following 

 segments with a fascia of short glittering golden pubescence ; the two 

 apical segments with long brown pubescence ; the abdomen is rufo- 

 testaceous at its base and beneath ; the apical margins of the segments 

 beneath thickly fringed with long pale-fulvous pubescence. 



Male. Rather smaller than the female, but closely resembling that 

 sex ; it differs in having the clypeus and scape of the antenna} yellow. 



Hab. Mexico. In the Collection of the British Museum. 



3. MegaciHssa luctuosa. 



M. aterrima ; thorace dense et breviter velutino-piloso, pilis nigris, flocco 

 post-femorali albo-lanuginoso ; alis nigro suffusis. 



Female. Length 10 lines. Black ; the pubescence on the cheeks 

 sooty-black ; the clypeus with a central broad longitudinal depression ; 

 the pubescence on the face black. The thorax densely clothed with 

 black pubescence above, having a velvety appearance ; beneath, the 

 pubescence is more of a brown or sooty-black ; the floccus on the 

 posterior femora white, dense and woolly; the wings dark-fuscous. 

 Abdomen nigro-ameous above ; the two apical segments thinly clothed 

 with black pubescence ; beneath, the basal segment has a patch of short 

 pale pubescence on each side ; the apical margins of the segments with 

 a fringe of long sooty-black pubescence. 



Hab. Mexico. In the Collection of the British Museum. 



