310 Proceedings of the Royal Irish Academy. 



The nature of the spieulation is also a character on which great reliance 

 may he placed as a specific determinant; and, in the case of Scirpearia, it has 

 proved to be of great value. 



Very good examples of this may be seen in the great contrast between 

 the spicules of Scirpearin profunda and Scirpearia alba, or between Scirpearia. 

 flagcUum and Scirpearia ramosa, or between Scirpearia furcata and Scirpearia 

 thomsoni. 



By means, then, of a combination of these characters, it has been possible 

 to arrange the numerous specimens which have been examined into certain 

 fairly definite groups. It will be seen that in the great majority of cases 

 eacli group is represented by a single species ; but where possible we have 

 suggested affinities. It seems preferable, however, to designate these at 

 present as groups rather than as species, although the latter procedure must 

 also be used for reference. 



It is imnecessary to enter into the details of each gioup here, as that is 

 much better left over until the various specimens are discussed; but we 

 submit the following classification : — 



SCIRPEARU. 

 DmsiON 1. — Main Longitudinal Canals, TWO in number: — 



(a) profunda-group, . Scirpearia j>rofunda exaend. 



„ . Scirpearia hicksoni n. sp. 



„ . . Scirpearia vernicosa n. sp. 



„ . . Scirpearia anomala n. sp. 



(b) pectinata-group, . Srirpearia pcctinata emend, 

 (f) elongata-gioup, Scirpearia elongata emend, 

 (rf) flagellum-group, . . Scirpearia fagcllum emend. 



(c) thomsoni-group, . . Scirpearia Ihomsojii n. sp. 

 (j/) alba-group, . Srirpearia alba emend. 



(j) aurantiaca-group, . Srirpearia aurantiaca emend. 



(A) furcata-group, . . Scirpearia furcala evaend. 



(i) andamanensis-group, . Scirpearia andamanensis n. sp. 



{j) ramosa-group, Srirpearia ramosa n. sp. 



(k) ceylonensis-group, . Scirpearia ceylonensis n. sp. 



(/) maculata-group, . . SriqKaria tnaculata emend. 



Division 2. — Main Longitudinal Canals, four in number : — 

 (o) quadrilineata-group, . Srirpearia quadrilintata n. 8.p. 



