37 8 Proceedings of the Royal Irish Academy. 



Prof. Eichters has studied the egg, which he found in material from 

 Samoa, and figured it in the " Moosfauna Australiens," 1 plate 17, fig. 10. It 

 is therefore appropriate that this species should be named in honour of the 

 naturalist who has done so much to extend the knowledge of the Water- 

 bears. 



Variety (figs. 13g-13h). — Processes of the egg shorter, very obtuse, and 

 rounded. Pattern on the shell sometimes exactly as described for the type, 

 sometimes with the polygons further divided by partitions. 



Embryo in the egg with the rods of the pharynx short and thick, the 

 length not more than twice the thickness. Adult quite typical. In the 

 embryo, and also in the adult, the middle rod of the pharynx often appears 

 shorter than the other two. This suggested that the animal might be 

 M. virgatus Murray, of which the egg is unknown. There are, however, 

 several differences : M. virgatus possesses eyes, has no comma, and the 

 claws are much thicker, with larger supplementary points. 



Habitat. — Am ong Tortula ruralis growing on the sandy sea-shore at 

 Louisburgh, March, 1911, plentiful. 



I have not seen any intermediate forms of eggs between the type and the 

 variety. 



M. richtersii is an animal which tends to re-establish faith in the constancy 

 of species of Water-bears. If the adult only were found, it might be identified 

 as one of the forms of hufelandii or harmsvjorthi, or some other species ; and 

 it would be regarded as one of the puzzling intermediate forms which throw 

 doubt on the validity of species. If the egg only were found, we would suspect 

 close relationship with M. areolatus, and no connexion with hufelandii and its 

 friends. Eeally the species is very distinct from both ; but we must know 

 both the adult and the egg before we perceive this. 



Macrobiotus virgatus Murray. 



The occurrence of this recently discovered Canadian species in Ireland is 

 interesting, in new of the fact that two other Canadian Water-bears and a 

 Canadian Bdelloid Eotifer were also found in Ireland. The species is another 

 link between Ireland and the Arctic, as it has been recorded for Pranz Josef 

 Land. 



Although unfortunately the egg has not yet been discovered, the species 

 has two good marks— the short middle rod in the pharynx, and the very thick 

 claws, thicker than in most species of the kvfelandii-gvowp. 



1 Zoo!, Jahrh. Abt, f. Sj-st. xxvi, Taf. 17, fig. 10, 1908. 



