382 C. R. OSTEX SACKEN'S PRODllOME 



are somcAvliat varialjle. The following segments arc Ijlack, -with yellow sides and posterior 

 margins. Venter yellowish at the Ixise, black at the end, the relative extent of Ijoth 

 colors beino" variable. Legs : nrevailinii: color reddish, with more or less brown at the Ijase 

 of the hind femora, the tip of the hind tibia? and the ends of the fom- posterior tarsi, the 

 latter half of the front tibiii} and the front tarsi brown, ^yings : costal cell infuscated, the 

 brown also occupying the proximal third of the first basal cell and encroaching very 

 slightly upon the second ; crossband limited posteriorly l:)y the intercalary A'ein, but filling 

 out the fourth posterior cell and thus reaching the hind margin; last section of the fifth 

 vein enveloped in a brownish cloud ; the interval between this cloud and the crossband is 

 hvaline. The hyaline triangle, separating the crossband from the apical spot does not 

 reach anteriorly bejond the second longitudinal vein ; thus the apical spot coalesces with 

 the crossband within the marginal cell ; posteriorly, the apical spot reaches a little Ijeyoud 

 the apex of the wing. 



Hah. Massachusetts (Beverly, Caraljridge, etc.,) collected by Messrs. Burgess and San- 

 born ; three females. A fourth female specimen, belonging to the Entomol. >Soc., Philad., 

 therefore pro1)al:)ly from the Middle States, agi'ees in all particidars with the others. 



Observation. Two female specimens (Illinois and Eed River of the North, by R. Ken- 

 nicott), which I have before me, differ in some particulars from the topical specimens of C 

 2nt(Uriis. The crossl^and docs not reach the hind margin, a considerable portion of the 

 fourth posterior cell not being filled out with bi'own ; the apical spot is somewhat narrower, 

 thj cloud on the last section of the fifth vein communicates with the crossband across the 

 base of the iiftli posterior cell ; the apex of the A-shaped spot on the second abdominal 

 segment coalesces with the black on the iirst segment, etc. This is probably a distinct spc- 



cies 



12. Chrysops montanus n. sp. 



2. A])ie;il spot eonncc-tt'(l with llie erosNbaiid, liyalinu tvianu'le between tliem not crossing the second lon- 

 gituilinal vein; bolli basal cells nearly hyaline, anil only .1 litllo infuscated at tlie proximal end; frontal 

 calldsity black ; facial tubercles yellowish-ferruginous; third and fourth abdominal segments with four black 

 longitmlinnl spots, alternating with yellow ones. 



Length, 8 nun. 



Feni'de. Face (including the facial callosities), yellowish-ferruginous; palpi redciish- 

 vellow ; antenna^ : first two joints reddish, the second mixed with Ijlack ; -both beset with 

 black hairs ; third joint lilack, somewhat reddish at the base. Frontal callosity black ; front 

 with vellowish-o-rav iiollcn. Thorax with the usual strii)es, the intermediate one with a 

 slightly more jellowish tinge than in C. ruham , the lateral ones yellow. Abdomen : first 

 two segments yellow; the first with a Ijlackish spot in the middle, under the scutellum ; 

 the second with a A-shaped Idack spot, both branches of which are less divaricate than in 

 C. ruhens ; in my three specimens this spot does not coalesce anteriorly with the spot of 

 the first segment ; the third segment shows four longitudinal black spots on yellow ground ; 

 the intermediate pair, which is the broader, is connected anteriorly, with the branches of 

 the A-shaped spot, and posteriorly, with similar spots on the fourth segment ; the lateral 

 spots of the third segment are continued only posteriorly by similar spots in the next seg- 



