100 THE AUSTRALIAN MUSEUM. 



Tlic tentacles are of 2 sizes (fig. 10) and are very numerous, about 60. 

 The larger tentacles have a short, thick basal part (about quarter of their 

 whole length), and the remainder is a flattened transparent expansion 

 recurved like a sickle. There are about 16 small atrial tentacles. 

 The dorsal tubercle has a simple oval aperture. 



The alimentary canal consists of a short wide oesophagus opening into 

 an elliptical or ovate stomach (fig. 8) which is about 3 mm. in length 

 and has about 7 longitudinal grooves on each side. On the anterior 

 edge of the stomach is a rounded projection into w r hich opens the duct 

 from the system of branched tubules with dilated ends (fig. 9) which 

 ramify over the intestine. The course of the alimentary canal is, first 

 posterior, then ventral, then anterior, then dorsal, and finally anterior. 

 The intestine is very long, about 7 mm. The intestine and rectum are 

 the same width and are narrower than the oesophagus. 



The reproductive organs are in the form of polycarps attached to the 

 mantle and projecting into the peribranchial cavity. Each is about 

 2-5 mm. in length. They are hermaphrodite (fig. 11), and the spermatic 

 vesicles are far more numerous than ova. All the ducts open into a 

 common central duct (fig. 12). 

 Locality. Port Jackson. 



The first specimen I examined of this species is only part of a colony, 

 not including the point of attachment. The specimen is a nearly square 

 piece which has evidently been cut off, and measures about 6.5 cm. by 

 5'5 cm., and 2 cm. in thickness. 



There has also been sent to me since an additional specimen found " on 

 rocks, at low water, in Chouder Bay, colour brick red," which measures 

 7'5 cm. in length and about the same in greatest breadth. It is 2'2 cm. 

 in thickness. 



[The following Polystyelid has also been recorded from Australian 

 seas : 



Synstyela incrustans, Herdm., Thursday Is.] 



Family II. BOTRYLLID^, Giard, 1872. 



Colony usually thin and encrusting, sometimes in the form of thick 

 fleshy masses. 



Systems circular, elliptical, or forming branched lines. Common 

 cloacal openings distinct, usually lobed. 



Ascidiozooids short, and not divided into regions. 



