220 Bulletin American Museum of Natural History. [Vol. XXXII, 



ECHINOIDEA 



Eucidaris thouarsii. 



Cidaris thouarsii Agassiz and Desor, 1846. Ann. Sci. Nat., Vol. 6, p. 326. 

 Encidaris thouarsii Doderlein, 1887. Jap. Seeigel, p. 42. 



There is only a single specimen, a small one, from San Josef Island, 

 Gulf of California. 



Centrostephanus coronatus. 



Echinodiadema coronata Verrill, 1867. Trans. Conn. Acad., Vol. 1, p. 294. 

 Centrostephanus coronatus A. Agassiz, 1872. Rev. Ech., Pt. 1, p. 97. 



This little known species is represented simply by young individuals, 

 the largest only 25 mm. h. d. 1 



San Josef Island, Gulf of California. 

 San Esteban Island, Gulf of California. 

 Agua Verde Bay, east coast of Lower California. 

 Five specimens. 



Arbacia incisa comb. nov. 



Echinocidaris incisa A. Agassiz, 1863. Bull. M. C Z., Vol. 1, p. 20. 



(= Arbacia stellata, Echinus stellatus de Blainville, 1825, non Gmelin, 1788). 



Since it is certain that Echinus stellatus of de Blainville is not identical 

 with Echinus stellatus Gmelin, it is clear that the name cannot be used for 

 de Blainville's species even though we do not know at present what species 

 Gmelin had in mind. A. Agassiz's name seems to be the first available 

 one. The species is characteristic of the Panamic region and while its 

 northern limit is not yet definitely known, it is probably south of the 

 United States. In 1901, I published (Proc. Boston Soc. Nat. Hist., Vol. 29, 

 pp. 331, 332) records of the occurrence of this and four other Panamic 

 echini and one or more Panamic starfishes, in Puget Sound. Some years 

 later it came out that the collections sent to me as from Puget Sound, 

 contained material not only from Puget Sound but from some point on the 

 Pacific coast south of the United States and also apparently from the West 

 Indies. Fisher (1911, Bull. U. S. Nat. Mus. No. 76) has recently called at- 

 tention to this regrettable fact, in the case of the starfishes and I therefore 



i This abbreviation for "horizontal diameter" will be used throughout this report. 



