352 PERCY SLADEN TRUST EXPEDITION 



Description op new species of Oribatid^. 

 Oribatinae. 



3. Oribata hrevis, n. sp. (PI. 17, fig. 1). 



Very small, less than '2 mm. in length, texture rather rough. Cephalothorax as long 

 as abdomen ; lamellae long, broad, blades on edge ; pseudostigmatic organs short and 

 clavate. Abdomen broad-oval. Pteromorphse short, with sharp anterior projections. 

 Legs short, monodactyle. 



Several specimens occurred in moss from Mt Alphonse. 



Though not as yet described, specimens of what appears to be the same species have 

 been received from British Guiana. 



4. Oribata elongata, n. sp. (PI. 17, fig. 5). 

 Length about '4 mm. 



Body long and narrow, only the claws of legs 4 appearing beyond it. Lamellae 

 narrow lateral ridges, without cusps or translamella ; pseudostigmatic organs long curved 

 rods with oval, roughened termination. No dividing line between cephalothorax and 

 abdomen. Pteromorphae long, narrow, only very slightly projecting forwards. Legs 

 monodactyle (or tridactyle, very heterodactyle). 



From moss, Mahd, Mt Alphonse. 



5. Oribata mammillata, n. sp. (PL 17, fig. 7). 

 Length about '4 mm. 



Elongate, the whole body covered with fine mammillae. Lamellae faint long ridges, 

 without cusps or translamella. Pseudostigmatic organs long, sinuous, clavate. Abdomen 

 long, with six very short clavate hairs at the posterior end ; pteromorphae short, strap-like, 

 rounded anteriorly, mammillate like the abdomen. Legs monodactyle, I and 2 strong with 

 slight protuberance on the penultimate article, 3 and 4 weak. 



Li moss from Silhouette. 



6. Oi'ibata longissima, n. sp. (PL 17, %■ 6). 



Very much like O. elo7igata, but still more elongate, the fourth pair of legs not nearly 

 attaining the end of the abdomen. Lamellae longer ; a faint translamella. The pseudo- 

 stigmatic organs are long and curved backwards ; in profile they appear filiform, but in 

 the dorsal aspect they are very slightly clavate. Legs monodactyle (or tridactyle, very 

 heterodactyle). 



In moss from Cascade Estate, Mah^. 



7. Oribata tnmcata, n. sp. (PL 17, fig- 4). 



Length about "45 mm. ; three specimens distinctly larger. 



An Oribata of the alata type ; cephalothorax unmarked, very convex, bordered by 

 very low ridge-like lamellae and translamella ; pseudostigmatic organs long, fairly stout 



