220 PROCEEDINGS OP THE ACADEMY OP 



confluent stripes ; the intermediate one broad ; the lateral ones abbreviated 

 before and extended over the section behind. (In some specimens scutum and 

 scutellum have a yellowish tinge) ; halteres pale with a dusky knob ; feet 

 black ; coxae pale yellowish-tawny, tinged with cinereous ; base of femora 

 also pale. Abdomen cinereous ; . <$ forceps tawny, (fig. 11); 9 ovipositor fer- 

 ruginous. Wings with a whitish, slightly milky tinge ; veins black ; stigma 

 indistinct; stigmatical cross-vein almost obsolete; base of the wing, as well 

 as the veins in that quarter, pale yellow. 



Numerous male and female specimens caught near Washington on the 19th of 

 May, 1859, on mossy stones in a creek. I found most of them performing a 

 a singular, sideways walk, close to the water's edge ; some of them were in copu- 

 lation. 



A. opalizans. Thorace silaceo, vittis infuscatis, pedibus pallide fuscis; 

 alis lacteis, opalizantibus, basi pallida ; long. lin. 2\ 2. 



Head cinereous ; proboscis yellow ; antennas (except the base) and palpi 

 fuscous. Thorax ochraceous, with three pale brown stripes, the lateral ones 

 sometimes indistinct ; halteres pale, knob slightly dusky ; feet tawny, slightly 

 infuscated at the tip of the femora ; coxae and base of femora pale. Abdomen 

 brownish; genitals paler. Wings like those of A. saxicola; they have a 

 still more milky, opalizing tinge ; their base is likewise pale, etc.; the color of 

 the veins, especially near the costa, is more yellowish. 



Six $ and four 9 specimens. Trenton Falls, N. Y., Dalton, Geo., and Mon- 

 treal, Canada. June, July, (nob.) 



The specimen from Montreal has black veins on the wings and fuscous feet, 

 the base only of the femora being pale. The specimen from Dalton has alto- 

 gether pale feet. 



ELEPHANTOMYrA nob. 



Proboscis almost as long as the body, very slender , filiform arcuated ; palpi inserted 

 at the tip of the proboscis ; first joint very short and almost coalescent with the 

 second ; both together are much longer than the third, the fourth a little 

 shorter, (conf. Prof. Loew's figures of the palpi ofToxorhina in Lin. Ent. 

 v. tab. ii.) Antennae apparently* 15-jointed, longer than the head, but hardly 

 reaching the base of the wings; first joint cylindrical, short ; second stout; 

 third oval, stout, the following joints subcylindrical, and more elongated towards 

 the tip of the antennae ; joints of the flagellum clothed with long verticils. Eyes 

 large, naked ; front narrow. Collare prolonged in a narrow, almost linear, 

 although moderately long neck. Feet long, slender, without spurs at the tips of 

 the tibia?. Pulvilli indistinct or none. Ungues without teeth on their under 

 side, broad at the base. Wings (somewhat like Meig. i. tab. vi, fig. 6,) with 

 one radial area, a discal and no petiolated areolet ; mediastinal vein and cross- 

 vein distinct; no stigmatical cross-vein; anal and axillary veins united by a little 

 cross-vein near the root of the wing. Forceps of the male consisting of a basal 

 piece and two falciform horny appendages, (fig. 12 represents one-half of the 

 forceps.) Ovipositor of the long, slender and pointed. 



The only species of this genus is the Limnobiorhynchus canadensis 

 described by Mr. Westwood in the Annates de la Socie'te' Entomologique de France, 

 1835, p. 683. I have to explain the reasons which induced me to form a new 

 genus of this species. 



Mr. Westwood has described two species of Limnobiorhynchus: the 

 (-J 1 and 9ofL. brasiliensis and the tf only ofL. canadensis. When, 

 therefore, he mentioned among the generic characters of Limnobiorhyn- 

 chus that the wings of the female differ from those of the male by having the radial 

 and cubital area coalescent in consequence of the obliteration of the radial vein, he 



* The incrassated third joint of the antennas seems to derive its size from the coales- 

 cence of two joints, so that in reality the antenna; are 16-jointed. 



[Aug. 



