190 



J. MURRAY ON WATER-BEARS, OR TARDIGRADA. 



8. Gullet elongated between the bearers and 



pharynx, flexible .... Diphascon. 

 Gullet not elongated and flexible . . Macrohiotus. 



Tabular Key to the Genera. 



Note. An x indicates that the genus always possesses the 

 character mentioned at the top of the column where it occurs, 

 and o or a, blank space that it never possesses the character. 

 An o and an x in the same column opposite the same genus 

 means that some species have, and others have not, the char- 

 acter. Thus, in Echiniscus, one species has tooth-bearers, and 

 one has been reported with rods in the pharynx. In Macrohiotus 

 and Dij)hascon some species have eyes, some have not. The 

 other characters are constant, so far as known. Macrohiotus 

 may exceptionally have the elongated gullet like Diphascon, but 

 it is not normal in any species, but due to some unexplained 

 cause. 



The claws of Echiniscus on one foot are all equal, free and 

 similar, except that some may have barbs. Those of Batillipes 

 are all similar in form, but the toes vary in length. 



* EcMniscoides has just been found (March, 1911) in W. Ireland by the 

 Clare Island Survey. Irish examples are soft-bodied, not armour-plated, 

 and have 2 pairs of spicules near the mouth, making 8 in all on the head. 



