18 



Oribata 



Subdiv. Ib. Sp. 20-39. Without any Tiiam. 



Sect. Ib l. Lam. large, horizontal, attached by post, edge only: 

 the 2 near together, leaving only a narrow cleft between. (Gen. Oribatella 

 Banks.) 



20. O. americana Haller 1884 0. a., G. Haller in: Arch. Naturg., v. 50 I p. 222 

 t, 15 f. 4. 



Im. Red-brown, polished. Lam. horizontal, very large, almost covering 

 Cephth. standing free except at hind edge, straight and nearly touching at 

 inner edges as in 0. tecta, but outer edge strongly and irregularly 

 toothed, ant. end truncated, concave, and without Lam. h.? Intlam. 

 hair extremely long, setiform. Psstg. org. moderate, somewhat clavate, 

 directed forward and inward. Kost. hairs clavate, hairy. Abd. almost 

 globular, with 2 longitudinal rows of long, setiform, strongly-curved hairs. 

 Legs short and thick. L. 390 |u. 



America. 



21. O. aquatica (Banks) 1895 Oribatella a., Banks in: Tr. Airier, ent. Soc, 

 v. 22 p. 9. 



Im. Dark reddish, a pale spot on Dors, of Abd. near ant. margin: 

 body very broad, almost circular, depressed, smooth. Lam. short, each 

 ending anteriorly in 2 spine-like projections, the lateral sinuate, 

 the median curved and bearing Lam. hair. Intlam. hair long, curved for- 

 ward; Psstg. org. moderate length, clavate. Ant. margin of Abd. convex 

 forward in middle. Ptm. oblong. Dors, of Abd. hairless. L. 550 u. 



On aquatic plants. New York State. 



22. O. berlesei Michael*) 1883 Oribates calcaratus (err., non C. L. Koch 1835!), 

 Berlese, A. M. S., fasc. 9 nr. 2 & Crypt. II, p. 65 | 1885 0. c. (err.), Canestrini, Prosp. 

 Acarof., v. 1 p. "17 || non 1880 Oribata quadricornuta, Michael in: J. R. micr. Soc., v. 3 

 p. 181 t. 4 f. 1—5. 



Im. Like 0. quadricornuta, but considerably smaller, black instead of 

 brown. Psstg. org. very long and strongly curved inward, instead of clavate. 

 Intlam. hair setiform instead of pectinated. Lam. touching anteriorly and 

 joined in centre by a cross-bar with a central branch running backward; 

 hairs on Dors, of Abd. much more numerous and placed at edge of Abd. 

 instead of far in. No pectinated Rost. hair ? and strong spines on Genual 

 and Tibia instead of pectinated hairs. L. ca. 450 |u. 



In moss and dead leaves. Italy. 



23. O. languida Mo. 1855 0. 1, Nicolet in: Arch. Mus. Paris, v.7 p. 434 t,4 f. 8. 



Im. Black, legs and ant. part of Ptm. brown. Like 0. ovalis, but 

 Dors, of Abd. covered with large, irregular transverse furrows, 

 or depressions (about 6). Ant. outer angle of Lam. a sharp, drawn out 

 point; post, margin of Abd. slightly undulated. Is this rare species a 

 deformity ? L. 420 u. 



France. 



*) Berlese identifies the species with 0. calcaratus C. L. Koch — apparently in 

 error; consequently this is nameless. I have therefore named the species in honor 

 of Berlese. A. D. Michael. 



