80 Proceedings of the Royal Physical Society. 



and before leaving it I may mention three problems that bave been before 

 me for some time. Does the food of these Ceratophylli consist only of 

 mammalian and avian blood ? Is there no probability of their attacking 

 invertebrates, 1 e.g., the lepidopterous and other larvae so frequently found 

 in the same nests. How again do they reach the nests of their hosts ? 

 Is the passage from one nest to another always effected on the 

 bird's body ? Or is it not possible that Ceratophylli seek the hosts' 

 nests of their own accord ? If not, are we to say that all fleas found 

 among leaves, herbage, stones, etc., have been dropped by passing hosts ? 

 It is highly probable that, where several species of birds resort to nesting 

 sites such as open moors, cliffs, caves, and ruins which provide easy access 

 from one point to another, Ceratophylli will spread without any direct 

 transference via the host's body. What finally becomes of the hordes of 

 fleas that are occasionally to be met with leaving nests ? Do they scatter 

 only to die ? Amongst more special points may be mentioned the method 

 of rupture of the cocoon. I have seen this happen repeatedly, but cannot 

 yet tell how it is effected. Possibly the frontal tubercle is employed 

 in the operation. 



Ceratophyllus rothschildi, spec. nov. 

 A pale, very distinct species. 



Head — Rather bare. Broadened in the $ towards the occiput, in the $ 

 relatively wider anteriorly. (See Fig. 1.) 

 From — With a marked tubercle in both sexes. Before and below the 

 eye two rows of bristles (3, 2 or 3). The lowest bristle of the 

 posterior row long, reaching well towards the end of the 3rd palpal 

 joint. 

 Occiput — Basal row of stout hairs, about 12. Row of fine short hairs 

 immediately on the upper edge of the antennal groove. Parallel to 

 this is a row of bristles (3), two anterior, above the 1st antennal 

 joint and one at the lower angle of the occiput. 2 

 Palpi — Equal to the rostrum ( $ ) or slightly shorter ( % ). The rostrum 

 . reaching to the tip of the fore coxse. 

 Thorax — 



Pronotum — With a comb of 32-34 teeth. Before this a row of 

 moderately strong bristles between which and the comb itself are 

 some minute hairs. 



1 The Zoological Record has the following reference :— 1882, Pulex feeding on larvae 

 of Tineina, Boden. Ent., xv., p. 70 ; but I. have not seen the article. 



2 Three other bristles, one at the lower angle of the pronotum and two on the 

 mesothoracic epimcion, continue this row backwards, 



