CATALOGUE OF TUNICATA. 91 



The branchial sac has 4 rows of stigmata, with 6 or 7 in a row. The 

 stigmata are small and rounded, and are about the same width as the 

 vessels between (fig. 4). The transverse vessels have muscle fibres. 



The dorsal lamina is represented by a few long and slender languets. 



The tentacles are 10 in number one larger dorsal and 9 very small 

 ones. 



The dorsal tubercle is a small circular opening immediately behind 

 the largest tentacle (fig. 6). 



The alimentary canal has a thick-walled oesophagus opening into an 

 oval stomach, with very thick walls and no folds (tig. 5). 



Gonads, both ova and the usual spermatic vesicle, with spirally 

 coiled vas deferens, are present. No larvae were present. 



Locality. Port Jackson. A number of small colonies growing over 

 other marine animals and sea- weeds. 



Leptoclinum fimbriatum, n. sp., PI. Did. I., figs. 18. 



The colony is flat, encrusting and expanded, so as to be of consider- 

 able size (fig. 1). It is of a dirty white colour, approaching in places a 

 lavender grey. The surface is even, but not smooth, as all the numerous 

 openings of Ascidiozooids form minute roughnesses. Cloacal apertures 

 are also present, and are ovate slits surrounded with a fringe of fine 

 processes (fig. 2). Size of a colony about 5 cm. each way. 



Test crowded with spicules, which are larger than those of the last 

 species, but not so numerous and not so densely packed. Consequently 

 the colony is not of such an opaque white tint. They become fewer 

 in the deeper parts of the test (fig. 4), but are numerous again in the 

 lower surface, which is hard and stony. There is a small dense clump 

 of spicules at each side of the thorax of each Ascidiozooid. The test 

 has numerous test cells, and a few vessel-like appendages (fig. 3). 



The Ascidiozooids are numerous, closely placed, and rather large. 

 They are distinctly visible on the surface, but there is no definite 

 arrangement. The body is divided into thorax and abdomen (fig. 6). 



The mantle has strong sphincter muscles at the branchial apertures, 

 delicate longitudinal fibres over the thorax (fig. 7), and strong retractor 

 muscles running into the test. 



The branchial sac has 4 rows of rather large stigmata (tig. 8), and 

 there may be a 5th row of much shorter ones. The stigmata are rather 

 wider than the vessels between. There are 7 or 8 stigmata in a row. 



The dorsal lamina is represented by a large languet on each trans- 

 verse vessel (tig. 8). 



