,oo DISCOVERY REPORTS 



together, only those on the margins of the colony lying some distance apart. Where the zooids are 

 separated the narrow basal stolons which unite them can be seen. Sand almost completely covers 

 both zooids and stolons. The zooids are ovoid, upright, may be slightly narrowed at the base, 

 and bear the two inconspicuous siphons at the upper end. The largest zooids are about 

 i cm. long. 



Tentacles. The oral tentacles, although closely spaced, number only about 50, whereas Kott 

 (1952) found about 100. 



Dorsal tubercle. The opening of the dorsal tubercle is a simple longitudinal slit. 



Branchial sac. In a large zooid the longitudinal branchial bars have the following arrangement: 

 dorsal line o (12) 5 (9) 6 endostyle. 



Gut. The gut is just as Kott described it, including the series of ligaments (Text-fig. 34, Ig.) 

 attached to the intestine. 



Gonads. Only the ovaries are present in zooids of the ' Discovery ' colony, there being no trace of 

 testes. On the right side there is a slightly curved row of about eight very small ovaries; on the left 

 side two rows diverge from the postero-ventral part of the body wall, one parallel to the endostyle 

 and the other following the course of the intestine (ov.). 



Endocarps. Large and small endocarps (en.) are scattered over much of the body wall. 



Distribution. Western and southern coasts of Australia; Tasmania. 



Subfamily Styelinae Herdman, 1881 

 Genus Cnemidocarpa Huntsman, 191 3 

 Cnemidocarpa pfefferi (Michaelsen) (Text-figs. 35A-C) 

 Styela pfefferi Michaelsen, 1898, p. 367. 



Occurrence. St. 42: S. Georgia, 120-204 m. St. 123: S. Georgia, 230-250 m. St. 159: S. 

 Georgia, 160 m. St. 1952: S. Shetlands, 367-383 m. 



External appearance. The largest specimen is 5-2 cm. high and 2-5 cm. wide, and the smallest 

 one 2-2 by 2-2 cm. The body is generally upright with the two quite prominent siphons a little distance 

 apart at the upper end. Shallow furrows divide the surface into large irregular areas. All the examples 

 in the ' Discovery ' collection are pale grey in the preserved state, with a fairly smooth surface which is 

 almost free of encrusting matter. 



Tentacles. These vary from ten to thirty-two according to the size of the specimen. 



Dorsal tubercle. The dorsal tubercle of the ' Discovery ' specimens is constant in form, having a 

 C-shaped slit with inrolled horns and the open interval facing forward. 



Gut. The stomach has twenty-four to thirty-one complete folds. 



Gonads (Text-figs. 35 A, B, C). In all specimens dissected there were two gonads on each side. 

 Each consists of a sinuous ovary (ov.), the sides of which have swellings, knobs, or short branches. 

 These short lateral branches are generally in pairs with the two limbs curved in towards each other. 

 The testis follicles (t) are arranged on the sides of the branches in a very characteristic manner (see 

 Text-fig. 35 B) and are closely united to the ovarian branches from the sides of which they scarcely 

 project even when well developed. The gonad is therefore of the Cnemidocarpa type, in which the 

 testis is bound closely to the ovary, within a common membrane. 



Remarks. This species has been confused with Styela paessleri, and van Name (1945) considered 

 them to be probably identical. The structure of the gonads is, however, quite different, although when 

 S. paessleri is at full maturity the testis is so large that it presses closely round the sides of the ovary 

 (see p. 115). The difference in the gonads of the two species will be best understood by reference to 





