343 



tissues of the ovary, and passes them on to the embrvo as 

 nutriment. 



The cases of \'iviparit}' known among insects have been enu- 

 merated by HoLMGRKX in 1903. We can add an additional 

 example of Ovarial Pregnancy, which may be expected to turn 

 out to be as interesting as that of Hemimerns, and wliich occurs 

 in the parasitic Rhynchota called Polyctcnidcc. After the dis- 

 covery of Viviparity in one species of this family, all the other 

 species available were examined, and we are now convinced 

 that Ovarial Pregnancy obtains in all as the onlv kind of repro- 

 duction. 



The Pulyctenidce are parasitic on bats, and occur in the tropics 

 of both hemispheres, but none have as yet been found in 

 Australasia. On account of their small size, the density of the 

 fur of their hosts, and the habit of keeping close to the skin of 

 the host, these parasites appear to be easily overlooked, and 

 therefore are rare in collections. Occasionally specimens in 

 various stages of immaturity are obtained together with adults 

 on the same individual of the host. In some instances the 

 abdomen of a female was found to be nearlv emptN-, apart from 

 the gut. The internal anatomy is still entirelv unknown. Most 

 of the specimens which we have studied — and winch belong 

 to the British Museum — were glued on cards, but are now 

 properly mounted in balsam, while others are preserved in 

 alcohol. 



The family is closely allied to the bed-bugs, with whicli they 

 have many peculiarities in common. The species are charac- 

 terised by the possession of one or more combs of short, flat 

 spines, an armature which they share with some other groups 

 of ectoparasites, e.g. Siphonaptcra, Nycteribiidce, and Platy- 

 psylla. Unlike Heminierus, the immature stages of the Polyctcnidce 

 differ more or less strongh' from the adult in the armature of 

 the exoskeleton. The earlier writers on the subject were not 

 aware of this fact, and therefore several errors crept into the 

 systematics of the family. The tirst-described species, Polyctcncs 

 nwlossus, was based on two specimens, one a mature male, erro- 

 neously considered to be the female, the penis being mistaken for 

 an ovipositor, and an inmiature example irroneously described as 

 an immature male. Eoctcncs spasjiuc \\'at( ili. {iSjn) was fmuuled 



