1908.] ON NEW SPECIES OF FLEAS. 617 



among lemurs, iiisectivora, cai'iiivora. But tlie feature of this 

 reptilian type is its generalised mammalian resemblances in dental 

 characteristics, which are highly specialised distinctions among 

 mammals, so that the teeth have undergone an evolution of 

 mammalian type. It is not to be anticipated that a complete 

 skeleton of Diademodon will make a closer approximation to that 

 of a mammal than is already evidenced by other Theriodont 

 reptiles ; but the dental characters emphasise the mammalian 

 approximations which have been found in the shoulder-girdle, 

 pelvic arch, and limb-bones. 



I propose to distinguish this species, characterised by the median 

 ridge on the palate, the ovate unworn multituberculate crowns of 

 the middle molars, the moderate interspace between the orbits, 

 and slender snout I'ounded above, as Diademodon eniomojjhonus. 

 The absence of wear to the crowns is only consistent with a diet 

 which did not involve ti-ituration. It is in contrast with the con- 

 dition in Diadetnodon hrowni, which it approximates in general 

 characters. 



G. New Siphonaptera. 

 By the Hon. N. Charles Rothschild, M.A., F.Z.S. 



[Received May 1, 1908.] 



(Plates XXYIII.-XXXI. *) 



Genus Pygiopsylla. 



Pygiopsylla Rothschild, Ent. Mon. Mag. (2) xvii. p. 221 (1906) 

 (type : hilli). 



The species belonging to this genus are easily distinguished 

 from Ceratophyllus Curtis (type of name : Mrimdinis) by the 

 sensory plate (so-called pygidium) of the ninth abdominal tergite 

 being strongly convex {cf. PI. XXX. fig. 14). All the species 

 are very hairy. They are inhabitants of the Old World, being- 

 known both from the Oriental and -Ethiopian Regions. Nine 

 species are known, namely : Mlli Rothschild (1904), novcu- 

 guinece Rothschild (1904), rohinsoni Rothschild (1905), colossus 

 Rothschild (1906), echidnce Denny (1843), ahcdce Rothschild (1904), 

 torvus Rothschild (1908), vjoodwardi Rothschikl (1904), and 

 rothschildi Rainb. (1905), the last two appearing to me to be but 

 doubtfully distinct from each other. In the present paper six 

 more species are described — namely, two from Aiistralia, two from 

 New Guinea, one from Ceylon, and one from West Africa 

 (Angola), — making in all 15 species of this genus. The wide 

 distribution of the genus renders it probable that these fifteen 

 forms are only a small percentage of the actually existing species 

 ■of Pygiopsylla. 



* For explanation of the Plates, see p. 629. 



