EWING'S PROTURAN SPECIES — BONET AND TUXEN 289 



Figure 57 gives the tergal chaetotaxy of the head and figure 58 that 

 of the thorax; figures 59-60 give that of abd. II and VII; all were 

 drawn by Bonet. 



The presence of a posterior row of setae in s VIII and a central seta 

 in the posterior row of t VIII is important. 



A row of teeth is found on the hind margin of terga IX and X; 

 about 20 small teeth are on t IX, and about 40 larger ones are on t X 

 (fig. 61). The hind margins of the pleura and sterna of these segments 

 also show rows of teeth (fig. 62). No row of teeth is present on the 

 pleuron of abd. VIII or V. 



The comb of abd. VIII (fig. 63) consists of 7-8 long teeth. As is 

 well known, this comb marks the lower border of the opening of the 

 large abdominal glands. A row of quite small teeth is also present on 

 the upper lid of this opening in the present species. 



There is a well developed labrum, nearly one-fourth the length of 

 the head (fig. 64). The maxillary palpi are long and the outermost 

 tusk of each seta is clearly defined as a fourth segment. All long 

 setae of the head are extremely long. 



The filamento di sostegno (fig. 65) is short. 



The species belongs, without doubt, to the genus Acerentomon as 

 defined by Berlese (1909). 



Acerentomon christensoni Ewing 



Figures 66-69 

 Acerentomon chrislensoni Ewing, 1940, p. 537. 



Several slides of this species are present. We have made descrip- 

 tions and drawings from the type slide which contains 4 females, and 

 a paratype slide with 3 females. Data of the type slide are, Brigham, 

 Utah, in peach orchard soil, April 20, 1938, L. D. Christenson collector. 

 The paratype slide bears the data, Medford, Oregon, in peach orchard 

 soil, Sept. 12, 1938, L. D. Christenson collector. 



The exterior side of the foretarsus (figs. 66-67) was drawn from a 

 specimen on the type slide, of one of the paratypes. The t 1 is clavate, 

 t 3 long, lancetlike. The difference from Acerentulus americanvs is 

 seen in b being longer than c, g longer than f, d short; and what is very 

 remarkable, a' is broad and long, and a small a" (=/31) is present. 

 In all these characters the foretarsus resembles that of Acerentulus 



Figures 56-63. — Acerentomon andrei Ewing: 56, foretarsus, interior side, holotype; 57, 

 chaetotaxy of head, holotype, drawn by Bonet; 58, chaetotaxy of thorax, holotype, 

 drawn by Bonet; 59, tergum of abd. II, holotype, drawn by Bonet; 60, tergum of abd. 

 VII, holotype, drawn by Bonet; 61, terga of abd. IX-X, holotype; 62, sterna of abd. 

 IX-X, holotype; 63, comb of abd. VIII, holotype. 



