162 MR. J. O. WESTWOOD ON THE LEPIDOPTEROUS 



acute point from which a single hranch is emitted, which forks into two branches, b 3 

 and b4>, b5 and b 5* arising together from the hind margin of the cell at three fourths of 

 its length from the base. C. inygdon (Pl. XXVIII. fig. 7) and C. inca agree with C. La- 

 treilUi in this respect. 



Among the Helicoinoid species with elongated fore wings, forming the genus Gazera, 

 Boisduval, C. cononia (Pl. XXIX. fig. 8) has a smaU postcostal cell, the 2nd branch of 

 the postcostal vein arising shortly before its extremity ; the 3rd and 4th branches arise 

 from its extremity a little distance apart, the short transverse branchlet connecting 

 b 5 with 6 5* springs close to the emission of 6 5 from the postcostal cell ; the 5th braneh 

 arises from the postcostal celL nearly opposite the base of the 2nd branch, and appears 

 to extend backwards to the origin of the Ist branch of the postcostal. The branches 

 b 5* and c 3* extend backwards, forming an acute angle within the discoidal ceU, and 

 emit a branch-Uke fold (discoidal nervure) towards the base of the wing ; c 3 Ukewise 

 is extended backwards, uniting with this discoidal nervure, forming with it a rudimental 

 (postdiscoidal) ceU. 



In C. equadoria (Pl. XXVIII. fig. 10) the arrangement of the postcostal branches 

 agrees with C. cononia, except that the Uttle transverse vein uniting branches b 5 and 

 b 5* is rather nearer the base of the wing. 



In C. mimica (PL XXIX. fig. 11) and C. linus (Pl. XXIX. fig. 9) the postdiscoidal ceU 

 is also present ; but it only enUts one branch at its acute extremity, which forks at some 

 Uttle distance beyond the ceU into the two branches b 3 and b 4. 



In C. truxilla (Pl. XXVIII. fig. 12), on the other hand, the postdiscoidal ceU is not 

 completed, there being no connexion between the branches 6 3 and 64; tlie relative 

 position of the postcostal branches is otherwise identical with that of C. Imus. 



In C. Marcel Serresi (Pl. XXIX. fig. 2), forming the type of Boisduvars genus 

 Ceretes, the small postdiscoidal ceU is present, emitting the branches 6 2, 6 3, 6 4, and 

 h 5 from its extremity at smaU distances apart, and the short transverse veinlet con- 

 necting b 5 and b 5* (and closing the discoidal ceU d c) from its hinder margin beyond 

 the middle. The discoidal ceU is traversed by a longitudital vein-Uke fold, the hinder 

 portion of the ceU [d c'*) forming a distinct ceU by the addition of a veiolet extending 

 backward from the basal junction of the median branches c 3* and c 3 — thus leaving 

 a narrow tract between it and the basal portion of the median vein c, which may be 

 called the premedian ceU, iJ.m. c. 



In C. chremes (Pl. XXIX. flg. 4) the arrangement is nearly simUar ; but the vein-Uke 

 fold in the discoidal ceU is less strongly defined, and the Uttle transverse vein which 

 closes the discoidal ceU does not arise from the hind margin of the posfccostal ceU, but 

 is pushed forwards and arises from the 5th postcostal branch close to its base. 



On comparing the figures of the wings of C. cacica (Pl. XXVIII. flgs. 6 and 6 «) vrith 

 those of C. Marcel Serresi (Pl. XXIX. figs. 2 and 3), it wUl be seen that the general 

 arrangement both of the veins and ceUs is identical. 



The arrangement of the veins of the kind wings has been comparatively neglected in 

 the Lepidoptera, although Dr. Boisduval has partiaUy, but not satisfactorUj^ used this 

 character in the generic distribution of his Castniaires. In the vaat majority of the 



