Mr. A. W. Waters on Australian Bryozoa. 91 



Busk says (' Challenger ' Report, p. 47) that he " could 

 not find any rosette-plates between the zooecia placed side by 

 side ; " but there are two elongate elliptical ones in the median 

 line of the lateral wall near each end. 



Loc. Bass's Straits ; QueensclifF; Portland (Victoria) ; 

 Station 16.^ A. Otf Twofold Bay; Tasmania; Shark Island, 

 8 fath. (New South Wales). 



16. Dimetopia spicata^ Busk. 



Loc. Bass's Straits ; Queenscliff ; Cape Otway ; Portland j 

 La P^rouse; New Zealand. 



17. Bugula neritina (L.). (PL IV. figs. 3 and 15.) 



For synonyms see Busk, Report of ' Cliallenger/ p. 42, and add Aca- 

 marchis neritina, Aud., Savigny's 'Egypte,' p. 69, pi. xi. fig. 1, 



Bugula neritina has always been described as without 

 avicularia ; but a common form from Ball's Head, Port Jack- 

 son, has them in abundance situated at the base of the 

 zooecia. The beak of the avicularium is prominent and the 

 mandible is large. The mandible is longer than that of 

 dentata^ but the beak is narrower, and, as in B. dentata and 

 B. avicularisj there are two small muscular prominences on the 

 proximal chitinous ridge. The shape of the mandibles of 

 B. dentata, B . Jlahellata, B. turhinata, B. avicularis, and B. 

 plumosa is almost identical, and they vary in size in the order 

 given. 



On the other hand Bugula Murrayana has a very long and 

 narrow mandible with the lateral processes curved downwards, 

 whereas the others have a straight lower edge. These " arti- 

 cular processes " are very marked in all the Buguloe, and 

 occur also in Memhra^iipora, Grihrilina, and Microporella, 

 showing that Mr. Busk attached too much importance to them 

 when he to a large extent based the family Adeonese on this 

 character. 



Mr. Hincks informs me that specimens from Zanzibar and 

 the Arabian Sea marked B. neritina have avicularia, and I 

 was told in the British Museum that an Asiatic specimen also 

 had avicularia ; but I am not sure whether the observations 

 have been contirmed. Specimens from Shark Island, 8 fath., 

 have no avicularia. 



18. Bugula dentata (Lamx.). (PI. IV. fig. 14.) 



Loc. Australia; New Zealand ; Tasmania; South Africa; 

 Ball's Head, Port Jackson, 12 fath. 



