On the Pierine Butterflies of the Genus Delias. 143 
fourth and fifth pruinose from a fine pubescence, which on 
the lateral bases of the second and third segments tends to 
form triangular marks. 
gd. Like the female, abdomen narrower. 
Hab. Ruidoso Creek, New Mexico; six collected by 
Prof. E. O. Wooton, viz. :—(1) no. 21, at 6600 feet, July 3, 
on Lrystmum ; (2) no. 49, a variety with the clypeus and 
supraclypeal area concolorous with the rest of the face, at 
7500 feet, July 6; (3) no. 24, July 8, on Mimulus luteus ; 
(4) no. 142, at 6600 feet, July 10, on Rhus; (5) no, 171, 
at 6600 feet, July 10, on Rhus; (6) no. 170, also on Rhus 
with the last. 
La Tenaja, near Santa Fé, N. M., collected by Miss Myrtle 
Boyle. 
Barts Fé, 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 Linum 
Lewisi in garden, July 12; (3) Ckll. 1407, July 10, Boyle 
coll.; (4) Ckll. 4242, Aug. 5; (5) CkIl. 4055, Aug. 2, on 
Clematis ligusticifolia; (6) Ckll. 4044 and 4046, Aug. 2, on 
Solidago canadensis. 
Las Cruces, N. M., March 31, 1896, on Sisymbrium. 
This is a species of the transition-zone, though a single 
specimen was taken at Las Cruces, in the Upper Sonoran. 
Ordinarily it is known especially by the dark nervures 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 conspecific (Wooton’s 
no. 49), did the character of the clypeal coloration fail. 
H. ruidosensis is very similar to H. Ashmeadii, Rob., from 
Florida, but the latter will at once be distinguished by the 
narrower face and the lively reddish-brown colour of the 
tegule; the second submarginal cell in Ashmeadii is much 
narrowed above, but in ruddosensis it is very little narrowed. 
Mesilla, New Mexico, U.S.A., 
May 9, 1897. 
XIII.—Revision of the Pierine Butterflies of the Genus Delias. 
By A. G. Burier, Ph.D. &c., Senior Assistant-Keeper, 
Zoological Department, British Museum. 
As recently as 1893 Ritter von Mitis essayed a revision of 
this genus in the German ‘ Iris,’ 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 
