DESCRIPTION OF SPECIES 65 



Branchial sac. In large zooids there are up to twenty-eight simple oral tentacles of alternating 

 sizes. The very small dorsal tubercle lies transversely and has a simple slit-like opening. Eleven or 

 twelve rows of narrow stigmata are present, the rows being separated by prominent raised bars. In 

 large zooids there may be as many as forty-five stigmata in a row. The dorsal languets are long and 

 slender. The branchial sac lies obliquely in the body and the rows of stigmata lie in a correspondingly 

 oblique position. 



Abdomen. The abdomen is much shorter and narrower than the thorax. 



Gut. The oesophagus (oes.) is long and narrow, and passes straight back to the stomach (st.), which 

 is ovoid and has smooth walls. Below the stomach the intestinal loop is short, but the rectum is very 

 long and in its anterior half diverges from the dorsal side of the branchial sac. The simple anus (a) 

 lies near the base of the atrial siphon. 



Remarks. This species has been described under a number of generic names, but it certainly belongs 

 to Podoclavella where Kott (1957) placed it, and not to Clavelina to which it was assigned by 

 Michaelsen (1930). 



The 'Discovery' material shows some differences from that described by Kott (1957), and is in 

 certain respects intermediate between P. cylindrica and P. australis (Herdman). But P. australis is 

 very probably a synonym of P. cylindrica, or at most a geographical form, as suggested by Kott. The 

 comparison of the only marked differences that is given in Table 20 shows the intermediate position 

 of the ' Discovery ' material, and strongly suggests that only one species is involved, P. cylindrica. 



Table 20 



Distribution. West and south coast of Australia; Bass Strait. 



Podoclavella kottae sp.n. (Text-figs. 16, 17; PI. II, fig. 1) 



Holotype. Size, largest zooid 12 cm. long. St. 934. 



Diagnosis of species. Zooids united only at base. Thorax short and ovoid; abdomen stalk-like 

 and many times larger than thorax. Atrial opening terminal; oral opening in basal half of thorax; 

 both openings with strong wide sphincter muscles. Branchial sac with up to twenty-seven rows of 

 stigmata, the anterior and posterior rows much shorter than the middle rows. Oesophagus and 

 intestine very long and narrow ; stomach ovoid and situated in a basal swelling of the stalk ; anus close 

 to oesophageal mouth. 



Occurrence. St. 934: North Island, New Zealand, 98-92 m. 



Colony (Text-fig. 16A; PL II, fig. 1). The specimen has eight zooids, the largest being 12 cm. long. 

 Fully developed zooids consist of a short thorax (th.) borne on a long slender stalk (sk.) which con- 

 stitutes the abdomen. The stalks have a basal swelling the lower part of which is united to a short 

 compact creeping stolon (sn.). The stalks are buff-coloured and the thoraces clear. 



Zoom (Text-fig. 16B, C). 



Thorax. The thorax of a well-developed zooid is 5-6 mm. long and 3-4 mm. wide. It is ovoid, 

 narrowest at its junction with the stalk and widest about one-third to one-half of its length up from 

 the stalk. The atrial siphon (a.s.) is terminal or almost so, and the oral siphon (o.s.) slightly behind 

 the middle of the thorax. Each opening is sessile and wide, the oral being the wider of the two. A wide 

 and conspicuous band of circular muscle surrounds each opening. About fourteen muscles radiate 



