EWING'S PROTTJRAN SPECIES — BONET AND TUXEN 285 



em podium is short; e:u = 8:28( = 0.3); a is long, c longer than b, 

 d very long, and f much longer than g. The t 3 is long, lancetlike, 

 t 1 long, claviform. The b' and c' are longer than a'. 



The chaetotaxy (figs. 47-50) schematically is as follows (pleurals as 

 usual included in the tcrgals) : 



It is characteristic that la in the posterior row of the terga is 

 situated anteriorly to the other setae of the row (fig. 47) ; also charac- 

 teristic are the setae missing in the anterior and posterior rows of the 

 terga. The s VIII has two posterior setae. Ewing drew t VII and 

 made a point of the next to lateral seta in the anterior row being 

 situated "in front of and out of line with the other setae of the row." 

 He did not realize, however, that the next to lateral seta in t VII is 

 No. 4, while in the first six terga it is No. 3, which as usual is situated 

 out of line, but behind the other setae of the row. 



The drawings of the chaetotaxy were made from two specimens 

 determined by Bonct with the label Luray Cavern, Virginia, June 4, 

 1948, E. W. Baker and F. Bonet collectors. The anterior apodeme 

 is only slightly branched, not as much as shown by Ewing. 



The comb on abd. VIII (fig. 51) has about 10 equally long teeth. 

 There is no other comb or row of teeth either on abd. V or VIII-X. 



The mouth parts of the holotype are drawn in figure 52. A short 

 labrum is present, a mandible with a small split, pointed maxilla lobes, 

 and a rather slender maxillary palpus. The whole as seen from the 

 side and showing the chaetotaxy is drawn in figure 53 by Bonet. 



The filamento di sostegno is shown in figure 54 from the holotype and 

 therefore from the side; it is short and without remarkable features. 



Because of the shape of the maxillary palpus (3-segmcnted, accord- 

 ing to Berlese, i.e., without a limit between the outermost segment and 

 the tusk of hairs on its tip) and the very small labrum, we are inclined 

 to put the species in the genus Acerentulm without, however, having 

 made up our minds as to the justification of keeping Acerentulus and 

 Acerentomon apart, or even perhaps dividing them into more genera. 

 In extreme cases there seems to be no doubt that the species belongs to 

 one or the other genus, but some cases are doubtful. Therefore, for 

 the present, the species should be called Acerentulus americanus 

 (Ewing). 



