ON SOME NEW OR LITTLE-KNOWN ACARI. 971 



47. On some New or Little-known Species o£ Acari. 

 By Stanley Hirst, F.Z.S. 



(Submitted for publication bj'^ pormission of tlie Trustees of the British Museum.) 

 [Uecoived September 10, 1923 : lleud November 6, 1923.] 

 (Text-figures 1-24.) 

 Trachytes ? austeni, sp. n. (Text-fig. 1.) 

 Deutonynijih. Body about twice as long as wide. Dorsal shield 

 undivided, covering the entire dorsal surface. It is furnished 

 with a slight median longitudinal ridge and a lateral ridge on 

 each side, these three ridges uniting at the anterior end of the 

 dorsum. Tube of peritreme reaching forwards on to the dorsal 

 surface above the coxa of the first leg, and then bending bade 

 again to form a short looji. There are a number of small round 

 platelets, each bearing a hair situated laterally on the soft 

 integument between dorsum and venter. A pair of similar 

 platelets is also present on the little triangular cone in which the 

 body terminates anteriorly. The ventral plates are not quite 

 like those of T. suviah-ensis Zacher ; the large anterior one 

 (called sterni-metasterni-genitale by Zacher) has the lateral 

 projection on each side opposite the interval between the second 

 and third coxje more angular than depicted by Zacher ; whilst 

 the cmal plate is larger than in T. atimatrensis, almost touching 

 the large anterior plate, and sometimes quite in contact with the 

 coxal (metapodial), the latter being very well-developed. All 

 the ventral plates are ornamented with minute spots, each 

 composed of a group of punctations. Anterior ventral plate 

 with five pairs of very short hairs. Anal plate with seven pairs 

 of hairs, including two pairs situated near the anal aperture. 

 Posteriorly there are several of the minute circular platelets,, 

 each caiiying a short hair. 



Length (including palpi) -48 mm.; width '22 mm. 



Host : A large fly {Pantophthalmus tabaninus Thunb.) j Brazil.. 



LjElaps ugandanus, sp. n. 



2 . A large and very strongly chitinized species. Sternal plate 

 very like that of L. muricola Tiagardh and L. giganteus Berlese ; 

 faint reticular markings are present on its surface. Genito- 

 veiitral plate widely expanded behind the coxse as in L. muricola, 

 etc. ; apparently there are no linear markings on it. Lateral 

 jdatelet near the last coxae much larger than is usually the case in 

 the genus Lcelaps and curiously shaped, ending in a sharp, almost 

 spiniform point anteriorly ; its surface is ornamented with a 

 rather irregular network of linear markings. Paired hairs on 

 anal plate slightly longer and also more slender than the unpairecl 



