816 Mr. H. Denny on Six new species of Parasites. 



narrow and unequal ; the fourth and fifth, forming the mesothorax 

 and nietathorax_, considerably enlarged, the lower portion of each 

 prolonged backwards into a tongue-like process and thickly punc- 

 tured. Alary plates moderate j sutural margins of the thorax and 

 abdomen ciliated above and below with large black bristles. Ab- 

 domen somewhat truncate posteriorly. Legs thick, orange-yel- 

 low; under surface of the femora, apex of the tibiae and tarsi 

 deep chestnut, densely armed with pitchy spines. Trochanters 

 very large, flat and securiform ; anterior femora somewhat sig- 

 moid. 



The specimen of this Pulex in my possession was given to me 

 by Mr. Gould, who found it on the Echidna Hystrix (Australian 

 Porcupine) in Van Diemen^s Land. Presuming it to be an un- 

 described species, I proposed for it the specific name of Echidna. 

 Several months subsequently however I found, on reference to 

 Mr.Westwood^s invaluable storehouse of entomology (the ^Modern 

 Classification of Insects^), that he had also a specimen of Pulex 

 from the same quadruped, sent to him from the same locahty by 

 Mr. R. H. Lewis, with the MS. name of Pulex Echidna. As 

 there is every probability that the two insects are of the same spe- 

 cies, I make no hesitation in quoting Mr. Lewis as the original 

 identifier, his specimen having doubtless been examined and 

 named before mine. This species resembles in some points the 

 Pulex Gigas of Kirby (Paun. Bor. Amer. p. 318. pi. 7. fig. 9.), and 

 is of nearly the same magnitude ; and although it is unknown from 

 what animal Dr. Richardson obtained it, yet, as the localities of 

 the two are so wide asunder and the zoology of the countries so 

 difi'erent, 1 feel justified in considering them specifically distinct. 



The specific character of Gigas is as follows : — " Ovatus, luteo- 

 testaceus, nigro-setosus ; thoracis segmento primo apice setis pecti- 

 nato ; secundi basi nigra ; antennis brevissimis, conicis ; femoribus 

 compressis, subovatis latissimis." 



EXPLANATION OF PLATE XVII. 



Fig. 1 . Ixodes himaculatus. 



Fig. 2. Hippopotamensis. 



Fig. 3. ' Rhinocerinus : 3 a, under view of the palpi and haustellum ; 



3 b, posterior leg of ditto. 



Fig. 4. Hydrosauri : 4 a, upper view of the palpi, &c. ; 4 h, posterior 



leg of ditto. 



Fig. 5. Lipoptena Pteropi : 5 a, anterior leg ; 5 b, upper view of the tarsus ; 

 5 c, penultimate joint of tarsus, showing the ungues, pulvillus and 

 setae; 5 d, single unguis much enlarged, showing the serrated under- 

 side ; 5 e, wing ; 5 /, one of the eyes ; 5 g, the pulvillus and setje 

 removed. 



Fig. 6. Pulex Echidnce : 6 a, magnified view of the head with the antennae 

 in situ ; 6 b, antennae ; 6 c, posterior leg ; 6 dj anterior leg. 



