300 



Thickness of stalk 



Number of pinnules 



Number of rays . 



Length of pro-rachidial margin of 



Breadth of insertion of largest pi 



Breadth of largest pinnule . 



Di.stance between pinnules 



The stalk is conical, with a swelling at the base of the rachis which is heart- 

 shaped when viewed from the meta-rachidial surface but oval from the pro- 

 rachidial. The meta-rachidial surface is covered by the overlapping pinnules 

 except for a short distance near the base. The majority of the pinnules are 

 lateral, but the lower rudimentary forms approach the pro-rachidial surface. 

 They are fan-shaped and contain twenty to twenty-four strong rays composed 

 of two to four spines which project at the margin in a very ragged manner. 

 They are thin and almost transparent. The zooid-plate is marginal and no 

 zooid-streak could be found. The polyps are disposed on either side of the 

 pinnules in five to six rows. There are no liiuy needles in the polyp-zone nor 

 in the spongy keel and stalk. It is noteworthy that in this specimen the axis 

 extends to the end of the rachis, whereas Kolliker describes a specimen in 

 which the axis ended about the middle. 



Locality : Penang. 



Previously recorded from Java. 



Pterocides esperi, Herklots. 



Two specimens of this species are present in the collection, 



Total length of colony . 



Length of rachis .... 



Breadth of rachis .... 



Length of stalk .... 



Thickness of stalk 



Number of pinnules 



Number of rays .... 



Length of pro-rachidial margin of largest pinnule 



Breadth of insertion of largest pinnule 



Breadth of largest pinnule . 



Distance between pinnules . 



This species is very variable. The following are the chief points worthy 

 of note in our specimens. The stem and keel are very hard but contain no 

 limy needles. Both the pro-rachidial and meta-rachidial surfaces are free through- 

 out their entire length. The pinnules are thin and almost sickle-shaped ; the 



