A REVISION OF TtlE GENUS STEGANOrOKELLA. 



269 



the zooeciuni (fig. 14 h), ''probably a modified radical tube." 

 The opening of the tube is well visible from above, being 

 shown in both A and b zocecia. These characters clearly 

 point to the species being identical with S. haddoni. Mac- 

 Gillivray suggests that his fig. 15 may be S. neozelanica. 

 The dimorphism of the zocecia, the large oral shelf of b, and 

 the obliquity of the opening of the tube make that determi- 

 nation improbable. 



I name this species in honour of my friend Dr. A. C 

 Haddon, whose collection from Torres Straits formed the 

 starting-point of the present paper. 



This species is probably of Hemescharan habit ; the largest 

 piece (c) measuring 36 X 33 mm. There is very little varia- 

 tion in the specimens I have examined. The zocecia are 

 commonly arranged with great regularity, and in some speci- 

 mens considerable parts of the colony are found in which 

 the arrangement is — 



In other cases the b zocecia may be less numerous, a 

 zooecium of this form being followed in the same line by 

 three, four, or even five a zocecia. The back is very charac- 

 teristic. It of course shows no trace of the insertion of the 

 cryptocyst. That of each zooecium is slightly convex, with 



