205 



Text-pig. 1. Skeleton spicules of Heteromeyenia ryderi. 



formation of a small percentage of the skeleton spicules. Exam- 

 ination of the gemmule spicules convinced him that this was an 

 unusual specimen of Heteromeyenia ryderi Potts rather than a new 

 variety or species. 



The typical form of skeleton spicule in this species is a long, 

 slender, slightly bent rod, gradually pointed at both ends, spined 

 entirely, except at the tips (a of text-fig. 1). 



The malformations found in this specimen were various, as 

 shown in the text-figure. Some of the spicules seemed to have 



