400 Professor Williston on the 



rather long silvery pubescent. Mesonotum opaque dark-brown or 

 black, with six series of yellowish-grey, more or less irregular 

 yellowish-grey spots, forming stripes ; scntellum opaque black ; 

 pleurae grey-pollinose. Abdomen shining black ; a narrow, yellow 

 pubescent, interrupted, posterior band on the second and third, 

 perhaps also on the fourth and fifth segments. Legs yellow ; the 

 femora except the immediate tip and the last joint of all the tarsi 

 black ; hind tibia? with a brown ring before its middle. Wings 

 yellowish hyaline ; an arcuate black band beginning at the tip of 

 the first vein, which is thickened and deep black, and extending to 

 the posterior edge of the wing ; third section of the costal vein a 

 little longer than the second. Length 1 h mm. 

 One specimen. St. Vincent. 



Hydrina. 



Eob. Desvoidy, Myod., 1830; Philygria, Stenhamraer, 

 Monogr. der Epliydr., 238, 1844. 



1. Hydrina nitida, n. sp. (PL XIII., figs. 145, wing; 

 145o, bead of ^ .) 



$ . Front composed almost wholly of the shining black verti- 

 cal triangle, leaving only a narrow margin opaque black and 

 silvery. Antennae black ; third joint light-yellow on the lower 

 half, much longer than broad ; arista short pectinate. Face very 

 narrow, gently convex from side to side, without grooves, receding 

 below, in colour silver-white ; bristles of the sides below weak ; 

 inferiorly the sides and the cheeks are shining black. Clypeus 

 concealed. Eyes very sparsely pubescent. Thorax deep black ; 

 mesonotum much shining ; scntellum opaque ; the pleural whitish 

 dusted. Abdomen shining black ; fourth segment about as long 

 as the two preceding together. Legs wholly light-yellow as are 

 also the cox«. "Wings yellowish or brownish hyaline ; third 

 section of the costal vein longer than the second ; penultimate 

 section of the fourth vein very short, the posterior cross-vein 

 remote from the border of the wing. Length 1 mm. 



One specimen. St. Vincent. Notwithstanding the 

 pectination of the arista I locate this species under 

 Hydrina, by reason of the comparative bareness of the 

 eyes, the structure of the face, and the position of the 

 posterior cross-vein. According to the canons of zoologi- 

 cal nomenclature the genus Hydra and its family ter- 

 mination Hydrinse do not conflict with the name Hydrina, 

 and it should have priority over Philygria. 



