September 1S97.] 



PSYCHE. 



115 



Yet, Osboni's resurrection of the Bur- 

 meisterian genus which has not for years 

 been used in this sense by European 

 authorities, would break it up. We can- 

 not cut out genera of wide extra-limital 

 occurrence to fit American species. 



Deltocephaliii bilineatus G. & B. 

 In Osborn's synopsis this species is 

 placed with those having " pronotum 

 short, more than twice broader than 

 long," while in the type the width of 

 the pronotum is somewhat less than 

 twice the length. 



Deltoccphalus albidus O. & B. This 

 species is not uncommon in various 

 localities in Colo, from Fort Collins to 

 Rabbit Ears Pass on the Continental 

 Divide. I have it also from Onaga, 

 Ks. (Crevecoeur). In the Colo, speci- 

 mens the pronotal lines are often quite 

 indistinct, while the elytral markings 

 are often very dense, size and structural 

 characters remaining constant. In the 

 " Review " the face of this species is 

 figured as having the genae with outer 

 margin evenly curved from eye to 

 clypeus, which would be a remarkable 

 character. They are angulate below 

 the eyes, as in all other known species 

 of the genus. 



Deltoccphalus injlattis O. & B. This 

 species is of frequent occurrence at Fort 

 Collins, Colo., and in the adjoining 

 foothills. 



Deltocephalus reflexits O. & B. I 

 have this species from New Bedford, 

 Mass. (Hough) ; North Windham, Ct. 

 (Morse) ; Onaga, Ks. (Crevecoeur) ; 

 and it also occurs here at Auburn, Ala. 



Deltocephalus concentrictts \"an D. 



Osborn without explanation, refers 

 Thamnotcttix flavomarginata to this 

 species and places them both in 

 Thamyiotcttix. Both forms are common 

 in the mountains of northern Colorado. 

 I possess large series which show no 

 intergradation between the two forms. 

 Flavotnarginata at least deserves a 

 varietal name. The latter was described 

 from a single female which lacked the 

 inner transverse nervure on both sides. 

 However in a large series this is 

 exceptional. 



It seems to me as great an error to 

 depend upon characters drawn from the 

 vertex alone, as upon those from the 

 elytra alone. Errors in generic refer- 

 ence of Jassids are sure to occur as long 

 as species are described from one or a 

 few individuals taken in a single 

 region. Flavot?iarginata answers the 

 Burmeisterian characterization of the 

 genus as closely as do some of the species 

 referred unquestionably to Deltoce- 

 phalushy Osborn. As characterized by 

 Burmeister, the width of vertex between 

 the eves should scarcely equal the 

 length. Yet, for instance, signatifrotis 

 placed as unquestioned Deltocephalus 

 by Osborn, according to two of the 

 latter's own figures, has the width of 

 vertex between the eyes nearly a half 

 greater than the length at middle. 



A proper understanding of some of 

 our dimorphic Jassids is nearly impos- 

 sible to any except those who are doing 

 work similar to Prof. Osborn's, yet this 

 reference, which I do not say is incorrect, 

 is made entirely without expkination or 

 even indicated evidence. 



