TARDIGRADA: CANADA 161 



mouth are prominent and the cirri short. Seta a measures about 50 M in length. It 

 is thicker than in any known species except E. cornutus, Richters, but it scarcely 

 tapers at all, and has a blunt rounded end. The " auricle " at its base is large and 

 of triangular form. The first median plate is separated from the plate in front of it 

 by a broad space. The second median is divided into two dotted portions by a 

 transverse plain band. Each plate of the pairs is divided into two unequal parts by 

 a line which runs parallel with its anterior border, the narrow part in front forming 

 a prominent roll which continues round the side and shows in the outline. The 

 granulation is of the sort which makes the plates seem cribrose. The dots seem to 

 perforate the plate ; they are unequal in size and are separated by irregular spaces. 

 The lumbar plate has four facets, the posterior one obscurely divided into two. 



The processes of the fringe are few (about eight to ten) ; they are narrow and 

 acute, and are separated by small spaces. The claws are large, about 25 /u in length. 

 The inner cla,ws of the fourth legs have small decurved barbs near their bases. 



Habitat. Among dry moss from the woods on the shore of the Lake of the 

 Woods, Ontario. 



E. sylvanus belongs to a group of species of which E. arctomys may be taken as 

 the type. These have nine or ten plates, segments V. and VI. have completely 

 coalesced, and there are no processes, dorsal or lateral, on the body, after seta a. 

 This section of the genus includes ten forms previously known, and three others, in 

 addition to E. sylvanus, are described in this paper. Two of these forms (macromastix 

 and exarmatus) were described merely as varieties. 



Most of these species differ in conspicuous characters from E. sylvanus. The 

 thick seta a alone separates it from all of them. Other distinguishing points are 

 here given briefly. Four species have seta a extremely long (macromastix, wendti, 

 reticulatus, tessellatm], four species have no fringe (elegans, intermedius, arctomys, 

 exarmatus), two species have totally different surface markings (spiculifer, bigranu- 

 latus). There remain three species which bear a closer resemblance to E. sylvanus. 

 E, viridis and E. macronyx have, like E. sylvanus, very large claws. E. viridis has 

 the surface dots very large, and seta a very short and fine. E. macronyx has 

 extremely fine and close dots, no barbs on any claws, and only the fourth legs have 

 large claws. 



E. kerguelensis is nearest to E. sylvanus. It has shorter claws and seta a is 

 slender. It is also considerably smaller (165 n, according to Richters, but Australian 

 examples larger, 225 n; sylvanus, 275 /"). 



Echiniscus intermedius, Murray (Plate XX. Figs. 52a, 526) 



Characters of Canadian variety. Small, hyaline or greyish. Mouth cirri with 

 large conical bases ; seta a long, no other processes on body. Three median plates, 

 first and second divided into two equal portions by transverse lines. Plates finely 



BRIT. ANTARCT. EXPED. 1907-9. VOL. T. Y 



