362 Mr. Hugh Scott on certain Nydcribiidse, 



than broad, with its hind margin deeply and rather widely emargi- 

 nate ; its base is bald, the rest of its surface bears strong, but not 

 very long bristles ; those at its hind angles are longer. At the base 

 of this plate is a dense group of strong dark spines on either side of 

 the body. Ventral surface of anal segment bearing some long bristles 

 medially. 



Dr. Speiser has recently described* a new species, P. 

 leptothrinax, from Madagascar. This is closely allied to 

 P. jenynsi. Judging from Speiser's description, the ^ ^ of 

 the two species are very much alike. Speiser states that 

 the ^ P. leptothrinax is distinguished " durch die wesentlich 

 dichter und audi auf der Fliiche beborsteten Tergitplatten." 

 In the $ P. jenynsi from Formosa, however, as stated above 

 tergites 2-4 bear bristles on their surfaces as well as their 

 hind margins. It may also be pointed out that the row of 

 long bristles just in front of the abdominal ctenidium in 

 both sexes, is present in the Formosan specimens of P. 

 jenynsi as well as P. le2)toihTinax. 



However much alike the males may be, there are 

 distinct differences in the females of the two species. The 

 basal tergite of P. jenipisi $ is of very distinctive form. 

 Instead of the two pairs of chitinous elevations on the 

 dorsal surface of the abdomen in P. leptotlio^inax ^ , P. 

 jenynsi has the single transverse chitinous piece (Fig. 8a). 

 Ventrally, the one pair of well-defined chitinous plates 

 (Fig. 4*1) followed by the chitinous segment (Fig. 4(;) are 

 distinctive and characteristic of P. jenynsi. In the con- 

 spicuously emarginate plate before the genital aperture 

 (Fig. 5), P. jenynsi $ seems to approach somewhat to P. 

 euxesta, Speiser. 



Larva. (Figs. 6, 7, 8.) — One $ specimen was found to be carry- 

 ing a larv^a, which projected behind it ; all the body of the larva 

 was outside that of the adult, except a small anterior portion which 

 was still within the widely-o^iened genital aperture. The larva, 

 when completely freed from the adult, was found to have not the 

 simple ellipsoidal form of previously described Nycteribiid larvae, 

 but the form shown in Fig. 6, the small anterior portion which was 

 still within the body of the mother being marked off from the 

 rest by a shai-p constriction. The anterior surface of this con- 

 stricted part is somewhat flattened in a nearly vertical direction 



* Voeltzkow, Reise in Ostafrika in den Jahren 1903-1905, IL 

 1908, p. 199. (Stuttgart). 



