38 THE entomologist's record, 



parallel rows of bristles, and an additional bristle under the stigma. The first 

 abdominal tergite bears two series of long hairs, the next six have a single series 

 only. The sternite of the second segment {i.e., first sternite) in the male bears one 

 hair ventrally and two laterally, while in the female there is a lateral series of six 

 hairs. The next five sternites in the male all bear two long hairs. In the female 

 the third, fourth, fifth, and sixth sternites bear from seven to nine hairs. The 

 seventh sternite in the female bears two long and some short hairs. The eighth 

 sternite in the male is, as usual, enlarged, and bears many small hairs on its 

 ventral surface, and three strong spine-like bristles at its apical margin. The 

 ninth sternite in the female has a curved row of bristles along its hinder edge. At 

 the posterior edge of the seventh tergite there is a long bristle with two smaller 

 ones on each side of it in both sexes. The hinder coxae bear a transverse row of 

 short stout hairs on their outer surface. The hinder edges of the tibiae are deeply 

 notched. They bear on their outer surface, near the hinder edge, one row of 

 bristles. The hind tibiae bear five pairs of bristles inclusive of the apical pair, the 

 third and fourth pair are close together, a single bristle is placed between the fourth 

 and apical pair, close to the latter. The bristles of the tarsi are very stout, these' 

 are absent, however, on the ventral surface medially, except at the apex. The 

 claws are very long, being more than half the length of the fifth tarsal joint. 

 Length 3-3'5mm. 



The type specimens foiTiid by Mr. W. D. Cowan, in Madagascar, 

 on Centetes ecaudatus, is in the British Musenni. 



Ceeatopsylla incekta, sp. nov. (figs. 2, 5, 6). — A very small and pale species, 

 having but one comb, and that on the prothorax, consisting of 28 teeth. The 

 portion of the head anterior to the antennal groove is relatively much shorter in 

 the male than in the female. The labial palx^i are very short, being about half the 

 length of the head. The metathoracic epimeron bears eighteen hairs in the female 

 and twelve in the male. Ail the tergites of the abdomen bear two rows of bristles ; 

 the seventh tergite bears one long bristle at its jposterior edge. All the tergites are 

 much thickened internally (see fig. 6). The tenth sternite in the male is much 

 reduced in size. On the surface of the middle hind coxae there are long hairs, and 

 the second segment of the anterior tarsi is longer than the first. Length 2mm. 



I have examined specimens of this insect from Nyctinomus jugidaris, 

 Peters, fomid by Mr. W. D. CoAvan, in Tamatave, Madagascar, and 

 also from Nyctinomus brachyjjterus, Peters, found by Mr. Hart, in 

 Sierra Leone. The type is in the British Museum. 

 Explanation of Plate II. 



1. Typhlopsylla tristis. Copulatory organs <? . 



2. CeratopSTjlla incerta. Head. 



3. Pidex madagascariensis. Copulatory organs <? , 



4. Typhlopsylla ingens. Copulatory organs J . 



5. Ceratopsylla incerta. Copulatory organs <? . 



6. Ceratopsylla incerta. Abdominal tergites showing thickening of skeleton 

 (diagram). 



Plebeius argus and Plebeius aegon. 



By J. W. TUTT, F.E.S. 



On the morning of August 4th, 1899, 1 caught at Simplon specimens of 

 undoubted P. cinjus and specimens of just as undoubted P. aeyon. The 

 former was abundant, the latter rare, on the flowery banks on the left 

 side of the valley directly above the village. The difficulty of defining the 

 differences that exist between these closely allied species is marvellous 

 when one considers the ease with which the males, at least, can be 

 distinguished at the first glance. In comparing the males the follow- 

 ing superficial differences were at once noticeable. P. aegon was of a 

 more distinctly violet tint {i.e., had a more pronounced tinge of reddish 

 in its tone), the costa of the forewings was more broadly white, the 

 apex rather rounder, the outer margin also rounded, and the 

 dark marginal border much more decided. The hindwings of P. aegon 



