British Oribatidce : Notes on New and Critical Species. 217 
Dorsum dull black, of the «ame texture as in mollicomus 
and edwardsii, with which the present species is nearly 
allied : pteromorphae of the same texture, long but narrow. 
Disk of dorsum flattened ; prodorsal spot indistinct. Dorsal 
hairs in four series, fine, rigid, acute. There is a straight 
transverse fold, like a scratch, in the dorsal integument, just 
above the posterior margin. 
West Allendale in sphagnum. I have not seen it below 
1,200 feet. The nymph is similar to those of the two allied 
species, and might easily be mistaken for an adult creature, 
the integument being greenish brown and partly chitinized. 
There are also traces of lamellte on the cephalothorax. The 
dorsal plate is extended laterally so as to cover wholly the 
two posterior pairs of legs which are thus quite invisible 
from above. 
O. orbicularis Koch. (Plate B, fig. 7). 
O. piriformis Nic. (Plate B. fig. 8). 
O. picipes Koch. (Plate B, fig. 10 ; Plate A, fig. 10). 
O. oblongus L. Koch. 
O. montivagus sp. n. (Plate A, fig. 3 ; Plate B, fig. 12). ' 
O. setosus Koch. (Plate B. fig. 9). 
O. fuscipes Koch. (Plate B. fig. 11.) 
These form a closely connected series characterized in 
the adult creature by well developed lamellae and trans- 
lamella, short bluntly clavate pseudostigmatic organs, and 
abdominal integument reticulate with very fine shallow 
furrows (the meshes usually minutely punctate), but always 
smooth and shining. They are similarly linked together by 
common characters in the immature state. The nymphs vary 
to some extent in the form of the abdomen, but there is 
always a dorsal scutum (of the same texture as in the adult 
but less chitinized), covering more or less of the abdomen. 
(Plate C, figs. 4, 10 ; the scutum in fig. 10 is left unshaded, 
and covers the whole dorsum except a very narrow band in 
front). 
The names cited above from Koch and Nicolet have not 
always been used in the same sense by different authors. I 
have tried to square my identifications with the figures and 
descriptions of the original authors, and add a table to make 
clear in what sense the names are here used. 
1. Sinus of translamella narrower than deep 
Do. do. as wide as deep, or wider 
2. Cusps of lamellae acute 
Do. do. truncate . . . . 
3. Dorsum bearing 4 series of setose hairs 
Do. without hairs 
4. Dorsum with submarginal fold in front 
Do. without any such fold . 
2. 
3 - 
setosus. 
fuscipes. 
6 . 
4 - 
montivagus. 
5 - 
1914 July 1. 
O 
