892 PROF. S. J. HICKSON ON THE 



convexities on the surface, sometimes between the spines, some- 

 times carrying the spines with them. They appear to be always 

 absent in the older branches and stems. Our knowledge is still 

 so very imperfect concerning the growth and relations of the 

 gonophores in the Stylasterina that it is not reasonable to use any 

 diflferences that may be observed in the characters of the ampullae 

 for purposes of classification. 



The questions to be answered are the following : — • 



1 . Are there any constant differences between the male and the 



female ampuUte ? 



2. Is there any correlation between the sex of the colonies and 



characters of the general structure of the ccenosteum ? 



These two questions could be answered without much difficulty 

 by the examination of a number of preserved specimens of the 

 'same species from the same locality. 



In Professor Benham's notes on the structure of a specimen 

 which probably corresponds with Errina {Ltibiopora) novce 

 zelandicB facies " Ramosa," I find the following remark : — " Each 

 ampulla seems to have a small pore (? dactylopore) on its surface." 

 In the specimen I have examined of this species I cannot find 

 these small pores on the ampullae. Yon Marenzeller also remarks 

 that the male ampvillee exhibit small dactylopores " in niedrigen 

 Spitzchen." 



In a previous paper (3) I have shown that, in the ripe male 

 gonophores of Distichopora and AUopora, the spermatozoa are 

 discharged by a spout-like seminal duct. In the case of the female 

 gonophore, however, the only way of escape of the embryo is by the 

 rupture of the whole surface of the ampulla. It seems possible, 

 therefore, that the pore on the ampulla mentioned by Professor 

 Benham may be for the opening of the seminal duct and that the 

 specimen may be a male. On the other hand, it must not be 

 assumed that when the surface of a specimen is marked by large 

 shallow depressions having the size and appearance of ruptured 

 ampullae, the specimen is necessarily a female colony, because in 

 the specimen of Errina {Lahiopora) capensis in which these 

 shallow depressions are very well-marked I found to my surprise 

 that it was a male colony. 



As regards the structure of the gonophores there is very little 

 to be said at present. The male gonophores of Errina (Lahiopora) 

 capensis exhibit a well-developed spadix (manubrium), and in this 

 respect the genus seems to resemble Distichopora and to differ 

 from AUopora. The only other spirit specimen I have received 

 was a small branch of Errina {Lahiopora) novcB zelandics facies 

 " Benhami," and this proved to be a female. The specimen was 

 not, however, in sufficiently good condition to enable me to study 

 the structure of the gonophore. 



Coenenchymal Canals. — From the two spirit specimens I have 

 ascertained certain isolated facts which may be of some use when 

 our knowledore of the srenus is extended. 



