On the Pieri'ne Butterjfies of (he Genus Delias. 143 



fourth and tilth piuinose from a rtne jjubesceuce, which on 

 the hitcral bases ot" the second and third segments tends to 

 form triangidar marks. 



(^ . Like the fi'male, abdomen narrower. 



JIah. Kuiddso Crrok, New ^Icxico ; six collected by 

 Prof. E. O. Wooton, viz. :— (1) no. 21, at G600 feet, July 3, 

 on Erysimum ; (2) no. 49, a variety with the clypeus and 

 su|naclyj)eal area concolorous with the rest of the face, at 

 7500 foot, July 6 ; (;5) no. 24, July o, on Mlmulus lufeus ; 

 (4) no. 142, at 6G00 feet, July 10, on Rhus; (5) no. 171, 

 at G600 feet, July 10, on Rhus-, (G) no. 170, also on Rhus 

 with the last. 



La Tenaja, near Santa Fc, N. M., collected by Miss Myrtle 

 Boyle. 



ISanta Fd, N. M., seven, as follows:— (1) Ckll. 1141, the 

 only male I have, unfortunately without its head, on alfalfa, 

 Andrews orchard, June 27 ; (2) Ckll. 3468, on Linuni 

 Lewisii in garden, July 12 ; (3) Ckll. 1407, July 10, Boyle 

 coll.; (4) Ckll. 4242, Aug. 5 ; (5) Ckll. 4055, Aug. 2, on 

 Clematis Ugusticifolia) (6) Ckll. 4044 and 404G, Aug. 2, on 

 Soil d( I (JO canadensis. 



Las Cruces, N. M., ^larch 31, 1896, on Sisymbrium. 



This is a species of the tra!isition-zone, tlmugli a sin,f>-le 

 specimen was taken at Las Cruces, in the Upper Sonoran. 

 Ordinarily it is known especially by the dark nervurcs and 

 stigma, not at all metallic abdomen, and contrasting colour of 

 the clypeus and supraclypeal area. The stigma may be 

 slightly pallid, a sort of rather dilute sepia, but never honey- 

 yellow; in one example only, apparently conspecitic (Wooton's 

 no. 49), did the character of the clypeal coloration fail. 



//. rmdosensis is very similar to //. Ashmeadii^ Rob., from 

 Florida, but the latter will at once be distinguished by the 

 narrower face and the lively reddish-brown colour of tiie 

 tegnlee; the second submarginal cell in Ashmeadii is much 

 narrowed above, but in ruidosensis it is very little narrowed. 



Mesilla, New Mexico, U.S.A., 

 May 9, 1897. 



XIIl. — Revision of the Pierine Butterflies of the Genus Delias. 

 By A.G.Butler, Ph.D. &c., Senior Assistant-Keeper, 

 Zoological Department, British Museum. 



As recently as 1893 Bitter von Mitis essayed a revision of 

 this genus in the German ' L-is,' pp. 100-153 ; he, however, 

 overlooked two or three described forms, and his material 

 evidently was far from rich enough to enable him to form a 



