No. 2. — Reports on the Results of Dredging, under the Supervision 

 of Alexander Agassiz, in the Caribbean Sea in 1878-79, and 

 along the Atlantic Coast of tlie United States during the Summer 

 of 1880, by the U. S. Coast Survey Steamer "Blake" Com- 

 mander J. E. Bartlett, U. S. K, Commanding. 



(Published by permission of Carlile P. Pattkkson, Supt. U. S. Coast and 



Geodetic Survey.) 



IX. 



Preliminary Report on the Echini^ by Alexander Agassiz. 



Cidaris tribuloides Bl. 



Station 142. 27 fathoms. Flannegan Passage. 



147. 250 " Off St. Kitts. 



Dorocidaris Bartletti A. Ag. n. sp. 



At St. Vincent in 95 fathoms, at Martinique in 210 fathoms, and at Montserrat 

 in 88 fathoms, a number of the peculiar spiny transversely banded radioles, similar 

 to Goniocidaris bispinosa were collected, some of -which I mentioned in the Pre- 

 Hminary Report of the Echini of the "Blake" Expedition for 1877-78, p. 186. 



From Barbados a few specimens were collected, showing that these spines 

 belong to a Dorocidaris which differs from B. papillata and D. Blakei in the 

 shape of the plates of the abactinal system. These specimens can at once be 

 distinguished from the above species by tlie large size of the triangular ocular 

 plates in contact with the extremities of the large anal plates inserted between 

 the genital plates. 



It may be that some of the specimens formerly referred to I), papillata 

 {D. abyssicold), with spines having serrated edges, belong to this species. 



VOL. VIII. — NO. 2. 



