REPORT ON THE TUN 10 ATA. 81 



Eugyra, Alder and Hancock'. 



Cynthia, Midler, Index Moll Groenl. 1842. In part, 



Eugyra, Aid. and Han., Hancock, On the larval state of Molgula, &c, Ann. and Mag. of Nat. 



Hist., ser. iv., vol. vi. p. 353, 1870. 

 MiJguIa, KuplVer, .lalnvslier. der ( 'mumiss., &e. 1871. In part, 

 Eugyra, Lacaze-Duthiers, Los Ascidies Simples des cotes de France, Arch, de ZooL exp6r. et 



gener., t. iv. p. 047. 1877. 

 Eugyra, Traustedt, Oversigt over de fra Danmark og dets nordlige Bilande Kjendte Ascidiaj 



Simplices, Vidensk. Medd. Nat. Foren. i Kj0benhavn, 1879-80, p. 428. 



Body globular, unattached. Branchial aperture six-lobed ; atrial four-lobed. 



Test usually thin and transparent, incrusted with sand or plain. 



Branchial Sac with no folds. Internal longitudinal liars few, but broad and 



ribbon-like. Infundibula formed of regularly coiled vessels, which form a 



double spiral meeting at the apex. 

 Tentacles compound. 

 Genitalia forming a single mass situated on the left side close to the intestine. 



The above definition of the genus is that of Hancock, slightly modified so as to admit 

 a species such as Euyyra Irryuelruensis, which has no glandular hairs on the outer surface 

 of the test and is not incrusted with sand, and so as to be in accordance with the nomen- 

 clature of parts adopted in this work. 



The main distinction between this genus and Molyula lies in the structure of the 

 branchial sac, Euyyra being characterised by the entire absence of folds, the broad 

 ribbon-bike internal longitudinal bars, and the large and regularly coiled infundibula. 



Euyyra kerguelenensis, Herdman (PI. VI. figs. 4-9). 



Eugyra licrgui'lma'ii.-i.-; Herdman, Preliminary Report, Proc. Roy. Soc. Edin., 18S0-81, p. 237. 



External Appearance. — The body is globular or slightly elongated dorso-ventrally 

 and is not compressed laterally ; it is not attached. The anterior end is broad, convex, and 

 flattened in the centre between the two apertures ; the posterior end is more convex. 

 The dorsal and ventral edges are nearly equally rounded; the sides are convex. The 

 apertures are both at the anterior end, they are not distant, and are conspicuous ; the 

 branchial is sessile, or almost so; the atrial is much more prominent, forming a short 

 cylindrical projection pointing directly anteriorly. 



The surface is even and smooth, with the exception of a few wrinkles round the 

 apertures. There is no sand adhering. 



The colour is a light transparent grey. 



Length, including the atrial siphon, 2 cm.; breadth, 1-8 cm. 



The Test is very thin and transparent, except on the atrial siphon and immediately 

 around the branchial aperture where it is thicker. 



