NEW OR LITTLE-KNOWN ACAllI. 999 



Host: The Elm-ba,ik Beetle {Scolytus destrnctor); a single 

 female specimen found on the larva of this beetle at Kew 

 10. X. 1922 {R. C. Fisher). 



Note.— This species seems to difier from Vitzthum's P. eccojito- 

 fjasteris in having a stout spinulo on the dorsal surface of the 

 second taisus. 



LisxKoi'uoiioiDES, gen. nov. 

 Body flattened dorso-ventrally instead of laterally, as is the 

 case in the genus Lislrophorus, etc. All legs Avith a sucker or 

 pul villus, that of the first leg being minute and that of the other 

 legs small also. Terminal segments of first and second leos 

 grooved ventrally, the sides of the groove being provided with 

 little knobs and processes for gripping the hair of the host. 



LlSTROPIIOROTDES JSTHIOPICUS, sp. n. (Text-fig. 24 a.) 

 (5 . Body moderately elongated. Capittdum shaped rather 

 like that of a louse, being roughly ti-iangular but with the lateral 

 angles salient ; it is short and wide. Posterior end of body in this 

 sex sometimes expanded and almost lobe-shaped as shown in 

 text-fig. 24 a ; in other specimens the sides of the posterior end of 

 the body are straighter (but this is perhaps due to distortion 

 through shrinkage). There are three pairs of hairs on the 

 posterior end of the body, but they are inconspicuous, two pairs 

 being very short and fine, and the lemaining pair not very long, 

 Anal suckers not distinct. Tarsi of anterior legs short and 

 modified as described above; the tarsi of the posterior legs are 

 rather long and fairly slender, but the other segments of these 

 limbs are rather stout. Posterior margin of third coxa furnished 

 with two blunt spurs, the inner one being fairly large. 



Length (including capitulum) 450 /a ; width 187 yu. 



Host : Gricetomys gambianus ; Accra {Scott-Macjie Coll.). 



LiSTROPHORUS BOTH^, sp. n. (Text-fig. 24 b, c, d.) 



S • Body narroAv and elongated, being about four times as long 

 as wide. Capitidicm also elongated and rather narrow ; its front 

 margin shaped as shown in text-fig. 24c, being only slightly 

 prominent in the middle. Posterior end of abdomen shaped as 

 shown in figure, terminating in a pair of very delicate lobe- 

 shaped lamina?. Just in front of these lobe-like structures there 

 is a more strongly chitinized curved line, which is probably the 

 real posterior margin of the body. A pair of long hairs spring 

 from the posterior end of the body. Anal suckers distinct but 

 small, and rounded in outline. Tarsus of first and second leg 

 furnished Avith two haii's with blunt ends, one of them being 

 rather long. 



$ . Body also elongated as in the male. Unfortunately our 

 female specimens are not well mounted, and therefore cannot be . 

 described. 



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