J. MURRAY ON WATER-BEARS, OR TARDIGRADA. 67 



Genus Lydella Dujardin (Fig. 3). 



The very minute marine species for which Dujardin formed 

 this genus in 1851 appears to have been seen by no one since 

 its discovery. It is easily distinguished from all other Tardi- 

 grada by possessing only one claw on each foot. It has many 

 other peculiarities, and approaches the genus Macrobiotics by 

 some characters, but appears to be nearer Echiniscus. The 

 long, curved setae on the head, with ear-shaped processes at 

 their bases, and the lateral setae on the body, correspond with 

 >tructures of Echiniscus. The curved teeth, with bearers, and 

 the rods in the pharynx, correspond with Ma/CftMoiius. There 

 is a forked bristle on each side of the mouth. The legs are 

 very long and slender, and are distinctly articulated. I can 

 only give a sketch copy of Dujardin's figure (Fig. 3). 



Literature. 



For the assistance of students it has been thought well to add 

 a bibliographical list which will include all the works in which 

 new species are described. Three-fourths of the works in the 

 appended list (those marked with an asterisk) come under this 

 heading. The others are the more important memoirs dealing 

 with the structure of the Tardigrada. 



1. Basse, A. "Beitrage zur Kenntnis des Baues der Tardi- 

 graden." Zeitsch./. Wiss. ZooL, Lxxx., 1905. 



*2. Doyere. "Memoire sur les Tardigrades." Ann. sc. nat., 

 Ser. II., t, 14, 18-10, pp. 269—361. 



*3. Dujardin, F. " Memoire sur un ver parasite . . . sur les 

 Tardigrades, etc." Ann, sc. nat., Ser. II., t. 10, 1838, pp. 

 181—185. 



*4. Ibid. "Sur les Tardigrades, etc." Ann. sc. nat., Ser. III., 



t. 15, 1851, pp. 160— 1G6. 

 *5. Ehrenberg. (Trion y chin m ursinum) Oken's Isis, 1834, 7 St., 



p. 710. 

 *6. Ibid. " Mikrogeologie." Bd. If., Plate 35b. 

 *7. Ibid. "Beitrag zur Bestimmung des stationaren mikro- 



scopischen Lebens in bis 20,000 Fuss Alpenhohe." Abh. 



I: Akad. d. Wiss. Berlin, 1859, p. 429. 



