174 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY. 



A. Agassiz removed to Dorocidaris ; and tribuloides (or possibly metularia ; 

 it matters little which), which remains thus as the type of Cidaris. 

 Moreover Brandt, who was the first writer to subdivide Cidaris, dis- 

 tinctly states that tribuloides is the type of Cidaris s. str., and as 

 "first reviser" he undoubtedly had the right to select the type. There 

 is therefore no need of upsetting a number of familiar names and caus- 

 ing considerable confusion by insisting on papillata as the type of 

 Cidaris. Indeed, if we are to discuss this question, imperialis has a 

 better claim than papillata to be the type of Cidaris, for it is undoubt- 

 edly the first species Leske names, though he has it confused with 

 papillata under the varietal name major. In resurrecting Lamarck's 

 name Cidarites, which is clearly a substitute for, and synonym of, Cidaris, 

 Doderlein violates the old principle " once a synonym, always a syno- 

 nym," and certainly if Dorocidaris A. Ag. is a synonym of Cidaris 

 Leske, as Doderlein says, it cannot be used for a subgenus of Cidarites. 

 It is surprising that so good a zoologist as Doderlein should have com- 

 mitted two such errors. Since Doderlein's Cidarites equals Cidaris 

 Mortensen and his " Cidaris " is equivalent to Dorocidaris A. Ag., 

 the latter can be added to our list of accepted genera, which will also 

 include several genera of recent Cidaridae adopted by Mortensen, 

 Doderlein, and Agassiz and Clark, as follows : — 



Dorocidaris A. Agassiz. Stereocidaris Poinel. 



Choiidrocidaris A. Agassiz. Acauthocidaris Mortensen. 



•■b" 



We may also add five genera of fossil Cidaridae, accepted by Pomel, 

 Doderlein, and Duncan, regarding which there can be little question : — 



Ortliocidaris Cotteau. Polycidaris Quenstedt. 



Temuocidaris Cotteau. Diplocidaris Desor. 



Tetracidaris Cotteau. 



The following genera are fully described and figured by A. Agassiz or 

 by A. Agassiz and Clark, and their validity is not likely to be questioned, 

 with the possible exception of Stephanocidaris, which some zoologists 

 may not wish to separate from Phyllacanthus. So far as the evidence 

 goes, however, it is fully entitled to recognition. 



Stephanocidaris A. Agassiz. Aporocidaris A. Agassiz and Clark. 



Centrocidaris A. Agassiz. Anomocidaris A. Agassiz and Clark. 



There still remain no less than 21 genera and several subgenera of 

 Cidaridae which have been proposed and are entitled to consideration. 



