136 ME. J. BLACKWALL ON THE MOTEMEKTS OE INSECTS 



tip of the wing ; discal transverse vein straight, parted by one-fourth 

 of its length from the border, and by very much more than its length 

 from the prsebrachial transverse vein. 



12. SoiTA PSiLoiDES. Mtts. Pallidc lutea, tibiis anticis femoribus 

 halteribusque pallide testaceis, alis cinereis apud venas subluridis vena 

 transversa discali fusco nebulosa. 



Male. Pale luteous, with black bristles. Femora and fore tibiae pale 

 testaceous. Wings cinereous, slightly lurid along the veins; veins 

 black, pale luteous towards the base ; discal transverse vein clouded 

 with brown hindward ; halteres pale testaceous. Length of the body 

 5 lines ; of the wings 8 lines. 



Subfam. Htdeomtzides, Fallen. 

 Gen. NoTiPHiLA, Fallen. 



13. NoTiPHiLA ORTALioiDES. Mas. Nigra, thoracc picco tomcntoso, 

 tarsis piceis, alis nigris lituris quatuor interiovibus parvis quatuorque 

 exterioribus majoribus transversis albis. 



Male. Black. Head and thorax with some black bristles. Eyes bare. 

 Antennae as long as the face ; third joint linear, much longer than the 

 second; arista plumose. Thorax with piceous tomentura. Tarsi 

 piceous. "Wings black, with eight white marks; four marks minute, 

 near the base ; four exterior, larger, transverse ; discal transverse vein 

 straight, parted by half its length from the border, and by very much 

 more than its length from the prsebrachial transverse vein. Length 

 of the body If line ; of the wings 3 lines. 



Facts relative to the Movements of Insects on Dry, Polished, 



Yertical Surfaces. By John Blackwall, IF.L.S. 



[Eead Nov. 17, 1864.] 



(Abstract.) 



As objections continue to be urged against the opinion that flies 

 and other insects of various species are enabled to move on the 

 vertical surfaces of highly polished bodies by the emission of an 

 adhesive fluid from the numerous hair-like papillse distributed 

 over the inferior surface of their pulvilli, the statement of a few 

 plain facts for the consideration of dissentients, and especially of 

 those who stiU. advocate the hypothesis that flies, in such instances 

 as those referred to above, are supported in their movements 

 mainly by the pressure of the atmosphere, may, pex'haps, be 

 deemed deserving of attention. 



