TUNICATA. i. 
Branchial Sae with four large folds on each side, separated by 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. 6,7. 2. b.) are wide and ribbon-like, and are far 
apart (except on the folds). The transverse vessels are of at least three different sizes, 
arranged symmetrically (Plate I., fig. 6). The meshes are elongated and may contain 
as many as twenty-five to thirty stigmata. The wall of the branchial sac is thrown 
into occasional undulations, as shown in fig. 6. 
Tentacles 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 large and complicated in form (Plate I., fig. 7), having broken up 
into several distinct spirals with the horns coiled inwards. 
Alimentary Canal very large, on the left side, cesophageal opening very far 
forward, within 5 cm. of the anterior end of the body, and leading by a short funnel- 
shaped cesophagus 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 cesophagus, is fringed with about ten simple or compound projections. 
Gonads énormous 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, g.). Numerous large and small irregularly shaped endocarps (figs. 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 seas, but is very much larger, and differs in details of 
Fic. 1.—Styela spectabilis, Fig. 2.—Styela spectabilis, 
from left side. from right side. ; 
(About one-third natural size.) (About one-third natural size.) 
structure. Although the two apertures differ so greatly in appearance (Plate I, 
figs. 2 and 3) in the preserved specimen, they are probably both widely open and more 
E 2 
