TUNICATA. 5 



Branchial Sac with four large folds on each side, separated hy wide interspaces 

 (Plate I., fig. 5). There are about six strong bars on a fold and five in the area 

 between two folds. The bars (fig. 6, /. /. b.) are wide and ril)bon-like, and are far 

 apart (except on the f(}lds). The transverse vessels are of at least throe different sizes, 

 arranged synnnetrically (Plate I., fig. G). The me.shes are elongated and may contain 

 as many as twenty-five to thirty stigmata. The wall of the branchial .sac is thrown 

 into occasional undulation.s, as shown in fig. 6. 



Tentncli'S large (15 mm. x 2 mm.), simple, about thirty in number; a few are 

 smaller, but there is no regular alternation. 



Dorsal Lamina a plain membrane, short and not very wide. 



Dorsal Tubercle lai-ge and complicated in form (Plate I., fig. 7), having biokcn vip 

 into several distinct spirals with the horns coiled inwards. 



Alimentary Canal very large, on the left side, oesophageal opening very far 

 forward, within 5 cm. of the anterior end of the body, and leading by a short funnel- 

 .shaped a?sophagus to a large .smooth -walled stomach (Plate I., fig. 8, St.). The 

 intestine is short and wide, and has the usual course (see fig. 8). The wide anus, 

 close to the oesophagus, is fringed with about ten simple or compound projections. 



Gonads enormous and placed on both sides of the body. They are like yellow 

 .sausages, fully 1 cm. in diameter, with small nipple-like ducts at their atrial ends 

 (fig. 8,//.). Numerous large and small irregularly .shaped endocarps (fig.s. 8 and 9) are 

 present on both .sides of the body ; they measure up to 2 "5 cm. in length. 



This very fine species is probably the largest Styela known. In .some respects it 

 recalls Styela rustica of Arctic sea.s, but is very much larger, and differs in details of 



V\o. 1 s:ij' ■' y ■ itabilit, 



from left Kido. 

 (AlxMit ime-tliirtl natural il/c.) 



l''i(i. 2. -Slyi'lii sjxxtabilix, 



from right 8ido. 

 (Alioiit olit'-lhlnl iintural sizf.) 



structure. .Uthough the two apertures differ .so greatly in appearance (Plate 1., 

 figs. 2 and 3) in the preserved specimen, they arc probably both widely open and more 



K 2 



