REPORT ON THE TUNICATA. 247 



The Branchial Sac is simple. The transverse vessels are all of one width ; they bear 

 horizontal membranes. No internal longitudinal bars are present. The stigmata are 

 short, and elongate-elliptical in shape. The interstigmatic vessels are strong. 



The Dorsal Lamina is reduced to a series of languets. These are short, conical, and 

 tentacular, and are separated by about their own length. Tiny spring from a narrow 

 membranous band. 



The Tentacles are short and stout ; the}- are about twenty in minilier, placed long and 

 short alternately. 



The Dorsal Tubercle is small and irregularly oval in outline; the horns project 

 laterally at the anterior end. 



This species forms a very elegant-looking colony of an elongated shape (PL XXXV. 

 fig. G). The posterior ends of the individuals are in close contact, and sink into a 

 common base or stolon, which forms the axis of the colony. The bodies of the separate 

 individuals are more or less club-shaped on account of the anterior end being much wider 

 than the posterior. 



The test is of a soft cartilaginous consistency, intermediate between the thin 

 gelatinous test of Clavelina lepadiformis, and the thick cartilaginous one of Clavelina 

 c ) tor mis. 



The branchial sac, though simple, is not delicate (PI. XXXV. fig. 7) ; the interstigmatic 

 fine vessels are strong, and nearly as broad as the stigmata. The transverse vessels are 

 moderately wide, and bear plain, not very wide horizontal membranes, which when 

 laid out flat scarcely cover even the tops of the stigmata immediately below them. The 

 ciliated stigmatic cells are short and rounded (PI. XXXV. fig. 9, sg.c). 



The languets are short and stout, and are placed on a narrow membranous hand 

 extending- alone the dorsal edge of the branchial sac. Their liases are continuous with the 

 horizontal membranes of the transverse vessels (PI. XXXV. fig. 8). 



The tentacles are short but strong. The larger ones are swollen about half-way up. 

 Jn one place two shorter tentacles occurred between a pair of larger ones (PL XXXV. 

 fig. 10, in.'). 



One colony of this species, consisting of about forty individuals, was dredged at Ber- 

 muda, in shallow water. 



Clavelina enormis, Herdman (PL XXXV. figs. 3-j). 



Clavelina enormis, Herdman, Prelim. Rep., Prop. Roy. Soc. E<lin., 1879-80, p. 725. 



External Appearance. — The individuals are united into a colony by their posterior 

 ends, which form a common base of irregular shape. The shape of each individual is 

 rudely oblong. The anterior end is wide, but irregular. The apertures are sessile, 

 inconspicuous, and not lobed ; they are both at the anterior end. 



