486 



TARDIGRADA 



genus. E. arctomys, Ehrb. ; E. mutaMlis, Murray ; E. islandicus, 

 Eichters ; E. gladiator, Murray ; E. ivendti, Ricliters ; E. reticulatus, 

 Murray ; E. oihonnae, Eichters ; E. gra7iulatus, Doy. ; E. spitzher- 

 gensis, Scourfield ;^ E. quadrisinnosiis, Eichters ; and E. muscicola, 

 Plate, are all British. More than one-half of these species are 



also Arctic, and E. arctomys is in 

 addition Antarctic. In fact, the group 

 is a very cosmopolitan one. The genus 

 is also widely distributed vertically, 

 specimens being found in cities on the 

 sea level and on mountains up to a 

 height of over 11,000 feet. 



1«.. Sub-genus ECHINISCOIDES 

 differs from the preceding in the num- 

 ber of the claws, the want of definition 

 in the dorsal plates, and in being marine. 

 The single species E. sigismundi, M. 

 Sell., is found amongst algae in the 

 North Sea (Ostend and Heligoland). 



2. Genus ZYDELLAr— The long, 

 thin legs of this genus have two seg- 

 ments, and in other respects approach 

 the Arthropod limb. Marine. Plate 

 suggests the 2iame L. dujardini for the 

 single species known. 



^8. Genus 3IACR0BI0TUS has a 

 Fig 25i).~i)ijJH(scoac/uienense, pjcrmented epidermis, but eye-spots may 



Plate, X about 100. (From J^ " ^ > J L J 



Plate.) ce, Brain ; k, thicken- be present or absent. The eggs are laid 

 Z IX. Sf'STltr one at a time, or many leave the body 



phagus ; p, ? salivary glands ; at OnCC. 

 2Jh, pharynx ; sa, blood cor- 

 puscles ; st, -stomach. 



g^enus is divided into 



They are either quite free 

 or enclosed in a cast-off cuticle. The 



many species 



and shows signs of disruption. They mostly live amongst moss ; 

 but M. macronyx, Doy., is said to live in fresh water. The 

 following species are recorded from North Britain : M. oher- 

 Ji duseri, Doy. ; M. Mifelandi, Schultze ; M. zetlandicvs, Murray: 

 M. intermedins, Plate; M. angusti, Murray; M. annulatus, Murray; 



1 P. Zool. Soc. 1897, p. 790. 



^ Hay, in P. Biol. Soc. TFashinifton, xix., 1906, i<. 46, states that tlie name 

 Lydclla, Dujardin, is ]>reoci'upied, and suggests as a substitute Micro/ i/da. 



