6 Transactions of the Society. 



Diaschiza gibba Ehrenberg. 



PL I. figs. 1 and la. 



Synonymy. 

 Furcularia gibba Ehrenberg. 

 Diaschiza semiaperta Gosse. 

 Furcularia gibba Gosse. 



BIBLIOGRAPHY. 



Ehrenberg, G. F. — Die Infusionsthierchen. Leipzig, 1838, p. 420, pi. 48, 



fig- 3. 

 Gosse, P. H. — Mandtic. Org. in class Eotif. Phil. Trans. Eoy. Soc. London, 



1855, p. 433, pi. 17, figs. 35-37. 

 Hudson & Gosse. — The Eotifera. London, 1889, vol. ii. p. 80, pi. 22, fig. 10 ; 



and vol. ii. p. 43, pi. 19, fig. 13. 



Spec. Cheer. — Body long, large ; back highly gibbous, laterally 

 compressed, abruptly falling off steep to the foot, fiat ventrally ; 

 face slightly prone ; lorica normal diaschiza type, somewhat 

 flexible ; dorsal cleft narrow, straight ; lateral cleft normal ; eye 

 small, frontal. ; foot short, stout ; toes about two-fifths the length 

 of the rest of the body, furcate, thin, style-shaped, slightly acute, 

 and slightly upcurved. 



Ehrenberg described this species as Furcularia gibba. Gosse, 

 observing the dorsal cleft, re-described it as Diaschiza semiaperta. 

 Then, in his account of Furcularia gibba, vol. ii. p. 43, he failed to 

 observe this cleft, which in some specimens is difficult to define. 

 PL xix. fig. 13, compared with pi. xxii. fig. 10, will show that 

 his two species are identical even to the jaws. 



This is the largest species of Diaschiza, varying from g 1 ^ in. 

 downwards. 



The very peculiar eye, which is small and absolutely frontal 

 (not semioccipital as in Gosse's drawing), consists of a hollow 

 hemisphere the flat front of which is clear and transparent, the 

 rest pigmented red. 



The foot-glands are very prominent. 



The setae on the foot are especially well marked. 



The toes vary in length, shape, and curvature. In some cases 

 they are almost straight, but never observed by us as straight as 

 drawn by Ehrenberg, pi. xlviii. fig. 3 ; and by Gosse, pi. xix. 

 fig. 13. In other cases they are distinctly recurved, as in Gosse, 

 pi. xxii. fig. 10. All gradations between these two extremes 

 have been noted at various times. As a rule they are thin, 

 tapering gradually to a point, but sometimes they are to be found 

 stouter at the base, yet we have never seen them quite so stout 

 as in Gosse, pi. xix. fig. 13. 



This rotifer has a habit of raising its toes over its back. 



