180 SPOLIA ZEYLANICA. 



description of the species. This is not the only species of 

 Miilleria that has irregularly formed teeth. I have found that 

 in most species, particularly in A. echinites, individuals may 

 occasionally have serrated teeth. The only specimen of 

 A. agassizi that I have examined has teeth very similar to 

 those of A. serratidens, but I cannot say whether this is a 

 regular character. In A. serratidens all the specimens I have 

 had occasion to examine have irregular teeth. 



The ventral pedicels are not arranged in series, but are 

 evenly scattered over the trivium. Frequently they are 

 white. The papillae are invariably black, and are scattered 

 over the bivium without definite arrangement. They are 

 smaller and less numerous than the pedicels. There are 

 twenty dark brown tentacles. 



Internal Structure. — The calcareous ring is similar to that 

 in most species of the sub-genus. There is one Polian vesicle. 

 In the type specimen described by me in 1903 there were 

 eight stone canals. In most of the Ceylon specimens recently 

 examined, the stone canal was single and was attached to the 

 right side of the dorsal mesentery. 



In a few cases I have observed from sixty to a hundred 

 small bodies evenly distributed on both sides of the dorsal 

 mesentery on a level with the Polian vesicle. These bodies 

 are extremely small, and the short stalk ends in a white 

 globular head "6 mm. in diameter. These problematic 

 bodies are similar in position and appearance to those described 

 by Selenka (22) in Actinopyga mauritiana {MilUeria varians). 



No other points in the internal structure call for special 

 comment, the respiratory trees and the Cuvierian organs 

 being typical. 



Spicides. — The spicules in the Ceylon specimens are similar 

 to those described by me from the type species. Usually, 

 owing to the dark pigment, the spicules are hard to see. In 

 the specimens from the Red Sea the spicules are much more 

 abundant, particularly in the ventral perisome, where, owing 

 to the absence of pigment and to their being very closely 

 packed, their presence is very readily detected. 



General Distribution, — Ceylon, Red Sea, Maldives. 



