662 MR JAMES MURRAY ON 



Nearest to M . furcatus, it is distinguished by the smaller egg, weaker spines, without 

 the basal circlet, weaker teeth, etc. 



Orkney, Ward Hill, Hoy, September 1906. 



M. echinogenitus, Richters (16). (Plate III. figs. 14a, 146.) 



Cysts of this species, Blantyre Moor. There is no outer case as in M. dispar ; the 

 cyst is yellow and of elliptical form, like the inner case of that species. 



Var. areolatus (Arctic Tardigrada, 12). 



An egg found in Loch Morar and on Ben Lawers appears to belong to this variety, 

 which is very widely distributed, from Spitsbergen to India. There are areolations, 

 round or hexagonal, between the spines of the egg ; the pharynx lacks the " comma," 

 and the claws are united for a greater distance above the base. 



o 



M. dispar, Murray (11). (Plate II. figs. 11a to 11a.) 



Specific characters. — Large, hyaline or brown ; claws of macronyx type, very 

 unequal ; pharynx large, shortly oval, rods of hufelandi type, viz. nut, long double rod, 

 shorter single rod ; furca of tooth very large ; dark eyes ; egg spiny ; spines short, sharp 

 cones, standing a little apart. 



Length up to 600m, pharynx 80m, egg 90m over the spines. 



There are usually two dorsal conical processes between the third and fourth legs 

 (fig. 11a), but these are very variable in size and may be obsolete. The egg is not 

 distinguishable from that of M. pullari, described in this paper, though that species has 

 quite different claws and pharynx. 



M. dispar lives in ponds and lakes. It undergoes a curious metamorphosis, first 

 casting its skin, then forming an outer case (fig. 1 la) and an inner case (fig. 1 1/), within 

 which it undergoes further changes which have not yet been completely traced. 



Localities. — Nerston Quarry, near Glasgow, 1904 ; Loch Tay, 1905 ; ponds near 

 Edinburgh (Evans) ; pond at Nairn ; North Uist ; Ronas Hill in Shetland ; Askomb Bog, 

 near York ; Spitsbergen, and Franz Josef Land. 



It is seen to be widely distributed in Britain and to range far north. Of its 

 southern range we have no knowledge. It is supposed to strongly resemble M. 

 macronyx, which has, however, a quite different egg, and it is possible that some of the 

 records of M. macronyx may refer to this species. It is closely related to M. ambiguus, 

 described in this paper, which has also a spiny egg, but of different form. 



A Diphascon-form of this species, with elongate gullet, was found near Edinburgh 

 (Evans). 



M. ambiguus, sp. n. (Plate II. figs. 9a to 9d.) 



Specific characters. — Large, hyaline ; claws of macronyx type, very unequal, those 

 of last legs less so ; pharynx large, shortly oval, of hufelandi type — a nut, a long 



