142 



1) The colony jointed, the two inner zooecia in each bifurcation 

 being divided into a distal and a pi-oximal calcified portion, connected 

 by a chitinous tube ; the vibracula far from reaching the central suture 

 of the branch. (The cryptocyst occupying about one-fourth of the whole 

 length of the zocecium. The proximal margin of the vibraculum sepa- 

 rated from the distal wall on the proximal side of it by a distance 

 which is at least half as large as the breadth of this wall; not in- 

 frequently avicularia along the middle of the branch; no opercular 

 spine) C. arachnoides Lam. 



1) The colony not jointed; the vibracuJa almost reaching or sur- 

 passing the central suture of the branch; 



2) The zooecia with a hammer-shaped opercular spine; the proximal 

 margin of the vibraculum is separated from the distal wall by a dis- 

 tance which is about half as large as half the breadth of the latter; 

 the vibraculum almost reaching the central suture of the branch; 

 the cryptocyst is a little shorter than half the length of the zoce- 

 cium C. retiformis Smitt '. 



2) No opercular spine; the proximal margin of the vibi-aculum 

 almost reaching the distal wall; the vibraculum reaching or surpassing 

 the central suture of the branch; the cryptocyst occupying about one- 

 third of the whole length of the zocecium C. caraibica n. sp. 



? C. simplex Busk^. 

 ? C. tenuis M. Gill. I 



On account of the remark made by Busk^ that the avicularia in the sutural 

 line of the branch in C. arachnoides do not seem to be developed in connection 

 with the separate zooecia, I may here call attention to the fact that Busk is 

 wrong in his supposition. On splitting a branch into its two lateral halves it will 

 easily be seen that these strongly compressed avicularia are given off from the 

 free continuation of the inner lateral margin of the zooecia. 



Rhabdozoum Wilson! Hincks, 

 Annals Nat. Hist. V Ser., Vol. X, pag. 160, PI. VIII, fig. 4. 



This peculiar form, of which I have been able to examine specimens from 

 W^estern Port and Port Phillip, Victoria, which I owe to the kindness of Mr. J. 

 Gabriel and Miss Jelly, is by Hincks wrongly referred to the Eucratiidae, a 



' 102, p. 16. ^ 8, p. 26. ' 68, p. 107. 



