REPORT ON THE TUNICATA. 243 



along the dorsal edge of the branchial sac, and is crossed transversely by the horizontal 

 membranes which bear the languets. At each side of this membranous area, just where 

 the stigmata commence, is a row of smaller languets, exactly similar in size, shape, and 

 position to the triangular flaps which support the internal longitudinal liars; these two 

 rows, however, at the sides of the dorsal lamina, bave no bars attached to their apices 

 (PL XXXVI. fig. 11). 



The tentacles are not numerous, and arc all of one length (PI. XXXVI. fig. 10, tn.). 

 They spring from a circular band of muscular fibres which forms the posterior end of the 

 branchial sphincter. 



The dorsal tubercle is ovate in outline, and lies in a shallow peritubercular area, out 

 of which it projects fully half way across the praebranchial zone to the base of the 

 tentacles (PL XXXVI. fig. 10, d.t.). The neural gland and the ganglion form a 

 rounded opaque mass, situated immediately posteriorly to the dorsal tubercle. 



One colony of Ecteinascidia fusca, formed of several individuals, was obtained at 

 Banda, Moluccas ; depth, 17 fathoms. 



Ecteinascidia turbinata, Herdman (PL XXXVI. figs. 1-0). 



Ecteinascidia turbinata, Herdman, Prelim. Rep., Proc. Roy. Soc. Edin., 1879-80, p. 721. 



External Appearance. — In this species many individuals are united into a colony by 

 delicate, much-branched, but short stolons. The shape of each individual is elongated, 

 and sometimes almost pyriform. The anterior three-fourths is nearly cylindrical, while 

 the posterior part tapers rapidly to a short slender stalk, continuous with the stolon. The 

 anterior end is broad, truncated or rounded. The apertures are sessile and minute, they 

 are both at the right side of the anterior end, and are not lobed. 



The surface is smooth. The colour is a light yellowish-brown. 



Length of the body, 3 cm.; breadth of the body (near the anterior end) 1 cm. 



TJie Test is thin and membranous ; it is transparent. 



The Mantle is thin. 



The Branchial Sac is simple. The internal longitudinal bars are narrow, but well 

 marked, they are borne on stout connecting ducts ; there are no papillae. The transv 

 vessels are all of one size, and are very wide ; no horizontal membranes are present. The 

 meshes are greatly elongated antero-posteriorly, and contain each two or three long narrow 

 stigmata. 



The Dorsal Lamina is represented by a series of tentacular languets. 



The Tentacles are simple and filiform, and are of three lengths placed alternately ; there 

 are about twenty of the long and twenty of the medium size, and forty of the short ones. 



The Dorsal Tubercle is elongated, and tapers posteriorly. The aperture is anterior, and 

 the horns are coiled. 



The Viscera extend slightly beyond the branchial sac posteriorly. 



(3DOL. CHALX. EXP. — r.YRT XVII. — 1S82.) R 32 



