inconspicuous. In the Astyci, on the other hand, the male is generally furnished with a discal 

 patch of peculiar scales crossing the median interspaces of the fore wings, usually in nn oblique 

 direction ; but sometimes the wing of the male is as simple as that of the female* In the male 

 MeetperideSi again, the posterior extremity of the alimentary canal is protected beneath by a 

 corneous sbrut.h, which extends beyond the centrum or body of the upper pair of abdominal 

 appendages, carrying the vent beyond the centrum ; while in the Astyci, the extremity of the 

 canal is not protected by any extruded sheath, but opens at the very base of the inferior wall 

 of the centrum/' * In 187G Mon. l J 2uil Mabille, who has considerably and specially studied 

 the Hrsperiida? commended this classification, f and in the following year enumerated and 

 described the species contained in the Brussels Museum under these main divisions, which he 

 again subdivided into several tribes. 



In 1878 a thoroughly exhaustive and model contribution to this problem appeared from 

 the pen of Dr. A. Speyer, J who notices, but does not altogether follow, Mr. Scudder. In the 

 revision of the European He&penidce, Dr. Speyer places considerable value on the presence or 

 absence of an appendage to the anterior tibiae as a character to be used in grouping the genera* 

 Dr. Speyer thus describes this structural character : — 11 The appendage to the anterior tibise 

 (epiphysis eruralis, schienblattcJien), a bare, mostly re ddish -yellow, blunt thorn-shaped, or lancet- 

 shaped, chitinous plate projects, in the Hesperiida, from the middle of the inner side of the 

 tibial and reaches to their end* It lies quite close to the tibiae, and its free surface is clothed 

 with a flat tuffc of hairs, so that the structure is sometimes not readily recognised." In his 

 diagnostic table of the genera, Dn Speyer uses the presence or absence of this character as a 

 means of sectional division. 



Herr C, Plotz* in 1879, gave a synopsis of genera, § and has since followed that paper by 

 the publication of a list of the species contained in many of those genera, whilst Mr, Moore 

 has further studied the family, and described many new genera, some of which embrace species 

 found in this fauna. 



Although reference has thus been made to much recent work devoted to the Ilesperiidx, it 

 is only too apparent that no natural classification and arrangement have yet been formulated 

 which are applicable to the whole family. As, however, in a work of this nature, some system 

 must be adopted, the writer has followed the same scheme of classification as was used with the 

 Lijaznida, and has divided the genera into two groups : — • 



Posterior wings more or less elongate, distinctly longer than broad, ... Ismenabia, 



Posterior wings more or less convex, about as broad as long. • - Ejuonotaria. 



Group ISM EN ARIA. 



This group is widely distributed, and it is in Tropical America, that the utmost elongation, 

 combined with caudate prolongation of the posterior wings, are found. 



* Bull. Buff. Soc. Nat. Sci, vol. L p. 197. + Aim. Soc, Ent, Fr. (5), vi. p. ^51 et «rg« 



I Stat. lint, Zuit. 1*73, pp. i .7— J!';i, and Engl, Triwifil. CiuiatL Eut. vol. x. pp. 121* 144, and 103. 

 § Stett. Ent. ZeiL 1B79, p. 175. 



