442 REPORT ON THE POLYZOA COLLECTED BY DR WILLEY 



The specimen from Brazil, moreover, has no avicularia and this appears to be 

 characteristic of Pourtales' form. The Lifu specimen has prominent avicularia along 

 the median line of the branch. The avicularian cell is very large with a serrated 

 edge : the mandible is triangular and acute. 



The ovicells are tj'pical, having the form characteristic of both species. Each 

 ovicell is crowned by a sessile avicularium and has a large membranous area in front. 



The collection contains some other specimens closely resembling the one already 

 described, but in these the fornix has a small lamina equally developed on both sides 

 of the stalk, while the mandible of the avicularium is longer. 



It will thus be seen that the Lifu specimens resemble Canda arachnoides and 

 differ from Cauda retifonnis in possessing avicularia and two spines on the upper 

 margin (in Smitt's figures, most of the zooecia bear only one spine) whereas it differs 

 from Canda arachnoides in the possession of a fornix and in the greater size of the 

 avicularium. 



4. Scrupocellaria scrupea, Busk. Busk, Brit. Mus. Cat., i. 24. 

 Only a few colonies occur. 



5. Scrupocellaria macandrei, Busk. Busk, Brit. Mus. Cat. i. 24. 

 Only one small piece occurs. 



6. Scrupocellaria annectens. MacGillivray. MacGill. Trans. Roy. Soc. Yict., 1886, 

 p. 184. 



There are two small, somewhat worn fragments which appear to belong to 

 MacGillivray's species. They agree with it in the general character of the zoarium, 

 the form of the zooecium and of its orifice, the character of the anterior avicularia, 

 and in the absence of the fornix in sterile zooecia. Here as in Scrupocellaria 

 annectens, there is a single vibraculum in the angle of bifurcation of the branch, and 

 the anterior avicularium at the base of the zooecium lying at the point of bifurcation 

 is larger than the others. The specimens differ from MacGillivray's species in possessing 

 three spines at the external angle of all the cells in addition to the spine placed at 

 the internal upper angle. The vibracula here seem to lie somewhat nearer the 

 middle line, and the apex of the vibracular cell from which the seta projects, stands 

 out as a prominent conical process. This feature is not shown in MacGillivray's 

 figure. No lateral avicularia are seen on the specimens. 



7. Didymia triserialis, n. sj). PL XLII., figs. 2 and 2 a. 



Cells joined side to side, varying from four to twenty-eight in each internode, 

 the ordinary zooecia being arranged biserially. At a bifurcation each cell of a primary 

 pair gives off a secondary pair at its summit ; ovicell smooth, imperforate, divided 

 by curved lines into three areas, occupying about half the length of the cell, the 

 orifice being a little above the centre ; ooecial cells placed one above the other 

 along the middle line of an internode interposed between the two lines of ordinary 

 zooecia. 



