THORNELY— MARINE POLYZOA OF THE INDIAN OCEAN 141 



Busk*, are small usually, but replaced here and there by a large one, raised on a prominent 

 rostrum and having a triangular mandible, the largest of these being situated below the 

 fork of a branch. Besides these there are large spatulate avicularia on the sides of the 

 branches near a fork, seen best from behind. Setaj are long and serrated. Ooecia have an 

 arched ridge across the front and are so numerous that the zooecia are partly concealed. 

 Cargados, 30 fath. 



13. Canda retiformis, Pourtales, Bull. Mus. Oomp. Zool., Camb. Mass., p. 110. 

 These specimens have the peculiarly long, pointed upper half to the fornix described 



by Miss Phillips t. There are sometimes two spines instead of one on the inner margin of 

 the zooecium. Where avicularia are present they are situated above the ocBcia. Vibracula 

 are not so long as figured by Smitt|. Ooecia have a semicircular area in front. There is 

 abundant material of this species. 



Amirante, 23 — 29 fath.; Saya de Malha, 55 fath.; Seychelles, 39 fath.; Cargados, 

 30 fath. 



14. Pollaploficium gilhertensis, Maplestone, Proc. Roy. Soc. Vict. n.s. p. 417, 1909. 

 Cargados, 80 fath.; Providence, 50 — 78 fath. ; Saya de Malha, 150 fath. ; Amirante, 



23 fath. 



15. Bugula dentata, Lamx. 



Acamarchis dentata, Lamx, Exp. Mdth. p. 6 ; Busk, Brit. Mus. Cat., i, p. 46. 



This species answers to Busk's description of B. de.ntata in all respects but that the 

 ocecia are not blue. They are set a little to one side, owing, apparently, to the three spines 

 occupying so much space on the outer margin of the zooecium. The spines are jointed and 

 are often broken off at the joints. 



Amirante, 29 — 34 fath. 



16. Bugula gracilis, Busk, Quart. Journ. Micro. Sci., vi, p. 125. 

 Amirante, 29 fath. 



17. Bugula neritina (Linn.). Waters, Journ. Linn. Soc. London, Zool., xxxi, 1909, 

 p. 135. 



There are several broken pieces of this species with avicularia present. 

 Providence, 50 — 78 fath. ; Amirante, 34 fath. ; Cargados. 



18. Bugula neritina, van minima, Waters, Journ. Linn. Soc. London, Zool., xxxi, 

 1909, p. 136. 



There are colonies ^ in. in height growing on seaweed. 



Cargados, reef; Providence, 50 — 78 fath. 



19. Bugula neritina, var. rubra, nov. (PI. 8, fig. 1). This variety has the shape of 

 zooecium, with pointed outer angle and the sideways position of the ooecium of B. neHtina. 

 The colonies are reddish brown in colour, robust and about 1^ in. in height. The whole 



* Rep. Challenger Exp., x, pt. xxx, p. 28. t Willey's Zool. Results, p. 4,39, 1900. 



I Flor. Bry., p. 16, 1873. 



