590 MR. A. G. BUTLER ON THE SPHINGID^. 



Genus 9. Cressonia, Grote and Robinson. 

 Cressonia, Gi-ote and Robinson, Proc. Ent. See. Phil. v. p. 186 (1865). 



1. Cressonia juglandis. 



Sphinx Jiifflandis, Smith and Abbot, Lep. Ins. Georg. vol. i. p. 57, pi. 29 (1797). 



Aynorpha dentata juglandis , Hiibner, Samml. exot. Schmett. i. pi. 171. figs. 1-4 (1806-24). 



Pohjptychus juglandis, Hiibner, Verz. bek. Schmett. p. 141. no. 1516 (1816). 



Smeiinthus juglandis, Harris, SOI. Journ. vol. xxxvi. p. 293 (1839) ; Strecker, Lep. Rhop. & Het. 



pt. 7, pi. vii. figs. 12, 13 (1873). 

 Cressonia juglandis, Grote and Robinson, Proc. Ent. Soc. Phil. vol. v. p. 161. no. 74 (1865). 

 Sphinx instibilis, Martyn, Psyche, pi. xx. fig. 49, and pi. 21. fig. 53 (1797). 



6 ? North America, 6 West Canada {Bush) ; East Florida {Douhleday). B.M. 



We have a pair of what seems to be a second species ; it is of a greyer tint and 

 half as large again, the transverse lines wider apart, and the primaries with central 

 band not darkened on the inner margin. I propose to call it C. rohinsonii, n. sp. 



2. Cressonia robinsonii. 



Cressonia robinsonii, Butler, supra. 



New York. Type, B.M. 



It is quite possible that the above may be a large form of C. juglandis ; but it differs 

 noticeably from our six examples of that species. 



3. Cressonia fallens '. 



S, Smerinthus pollens, Strecker, Lep. Rhop. & Het. pt. 7, p. 54, pi. vii. fig. 14 (1873). 



Texas. 



In Mr. Strecker's jocular strictures on the excellent subdivision of the Smerinthince 

 proposed by Mr. Grote, he exhibits a weakness in admitting that 8. juglandis and S. 

 •pollens might be placed in one genus, provided that uniformity of shape in the wings 

 were taken as the basis thereof I find that dissimilarity in the outline of the wings 

 is almost always accompanied by modification of the discocellular nervelets, which would 

 be sufficient in the eyes of any Lepidopterist to warrant generic separation. 



Genus 10. Paonias, Hiibner (restricted)^. 

 Paonias, Hiibner, Verz. bek. Schmett. p. 142 (1816). 



1. Paonias excsicatus. 



Sphinx exccecatus. Smith and Abbot, Lep. Ins. Georg. i. p. 49, pi. 25 (1797). 



' Mr. Grote is confident that this is only a variety of C. juglandis. It looks quite distinct. 

 '' At once distinguished from Calasymholus and Tripiogon by the form of the secondaries, which approach 

 Laoihoe in outline. 



