136 J. MURRAY 



hemispherical papillne ; no eyes ; trunk terminating posteriorly in little median 

 process ; legs long, obscurely three-jointed ; without fringe ; claws all similar, 

 without barbs ; stomach brownish. 



General description. Length, up to 230 M ; the teeth are very short, and the 

 pharynx nearly as broad as long. The processes on the head and mouth correspond 

 in number and position with those which characterise Echiniscus, but they differ 

 in several respects. In Echiniscus each of the principal sette (or horns) of the head 

 has at its base a separate triangular or oblong palp (or auricle). In Oreella this palp 

 is borne near the summit of the papilla from which the seta springs. In Echiniscus 

 the four processes near the mouth are all alike cirri, with minute conical bases ; in 

 Oreella the anterior pair are not cirri, but narrow cones. The palps seen in dorsal 

 view between the two pairs of cirri are here reduced to very small papillae. The 

 body papillee are low and rounded. They might be regarded as the rudiments of 

 the armour-plating, but they are not confined to definite areas, except that they do 

 not extend on to the ventral surface. Each leg consists of three joints, of which the 

 first and third are short, and the middle one longer. The feet are slightly webbed, 

 a membrane joining the bases of the claws. Beneath the skin an obscure irregular 

 areolation is seen. The stomach consists of a few large cells, which contain darker 

 brown spots. No mature eggs have been seen, but in some examples there appear 

 to be two very young eggs, with granular contents. 



Though in all essential features except the armour-plates very close to Echiniscus, 

 there are several little points in -which it differs from all known species of that genus. 

 These are, the modification of the anterior pair of processes near the mouth, the 

 elevation of the auricle on the same papilla which bears the seta a at the base of the 

 head, the absence of eyes, and the little median " tail" which terminates the body. 



Its movements are very slow. 



Habitat. Katoomba, in the Blue Mountains of New South Wales, altitude about 

 3000 feet. It was found in moss which had been dry for about a year. When 

 moistened about fifteen examples were found, of which only a few regained activity. 



Most of the genera of Tardigrada are closely related to the genus Echiniscus. 

 Though no other genus may have the elaborate armour-plating which protects 

 Echiniscus, all of them but Macrobiotus and Diphascon possess some of the numerous 

 palps and cirri which adorn the head of Echiniscus. Several genera (Halechiniscus, 

 Battilipes, Oreella) have the armature of the head almost identical with that of 

 Echiniscus. Other genera have the processes more or less modified, or reduced in 

 number (Microlyda [ = Lydelld], Echiniscoides, Tetrakentron, Milnesium). 



Milnesium, which departs furthest from Echiniscus, has eight palps on the head 

 which may be regarded as homologous with eight of the ten processes of Echiniscus. 

 In Echiniscus itself the processes may be reduced in number, though any departure 

 from the normal number is very rare. 



All the exclusively marine genera, five in number, are related to Echiniscus. All 



