■284 Transactions of the Society. 



a more or less straight course. It loves also to spin a fine thread 

 from its toes, and attaching it to any convenient object, remains 

 anchored, spinning round and round on its longer axis for a long 

 time on the same spot, while the vigorous action of the frontal 

 cilia, instead of propelling the animal forward, produces a strong 

 current of water towards the head which brings food to the mouth. 

 S. pcctinata and oblonga never spin round in this way. Contrary 

 to what other observers have reported, I have never seen 8. tremula 

 carry its eggs about. Dr. Zacharias has stated that in the North 

 of Germany this species, as well as S.pectinata, habitually carry their 

 eggs, which seems very strange if there be no error as to species. 



I have never seen S. tremula in salt water, and have little 

 doubt that when it has been reported as occurring in the sea or in 

 brackish tide pools, one of the marine species must have been 

 mistaken for it. 



Its largest size when full-grown I have found to be 292 yx 

 Q 7 in.) long by 149 fj, ( t }q in.) wide at the auricles. Young 

 animals are, of course, much smaller, and an average size would 

 be about 235 yu, ( T Jg in.) long by 124 jx {^ z in.) wide. 



Synchseta oblonga Ehrenberg. 

 PI. III. fig. 2 and PI. V. fig. 10. 



Synonymy. 

 Synchccta neglecta Zacharias. 



BIBLIOGRAPHY. 



Ehrenberg, C. G. — Abhandlung der Akad. d. Wiss. Berlin. 1831, p. 135 : 



1833, p. 221. 



Die Infusionsthierchen. Leipzig, 1838, p. 438, pi. 53, fig. 4. 



Hudson & Gosse. — The Botifera. London, 1889, vol. i. p. 127. 

 Zacharias, O. — Ueber die im Siisswasserplankton vorkommenden Syn- 



chseten. Biol. Centralblatt, Bd. ii. 1901, pp. 381-3. 



Spec. Char. — Body small, cone-shaped, somewhat oblong and 

 more or less swollen at sides, rounded in front ; auricles small ; 

 four frontal styles ; lateral antennae very small, situated two-thirds 

 down the sides of the body; eye red, cervical; foot short, narrow; 



EXPLANATION OF PLATE V. 



Fig. 8. — Syjuhssta grandis Zach. $ D orsal view, x 225. 



„ 9 n neapolitana sp. n. R ousa. ? Dorsal view, x 470. 



» 9« n » „ The toe and spur, x 1175. 



95 * 



" q c \ » ii ., The male, dorsal and Bide views. x680. 



n 1° », oblonga Ehrbg. The jaws. X 550. 



ii 10o „ „ A separated manubrium, x 550. 



„ 106 „ „ The unci, x 875. 



