CENTKOCIDARIS DOEDERLEINI. 20 



Centrocidaris a. Ag. 



Centrocidaris Doederleini A. Ag. 



Goniocidaris Doederleini, A. Ag., 1898. Bull. M. C. Z., XXXII, 5, p. 73, PI. III. fig. 1. 

 Centrocidaris Doederleini, A. Ag., 1904. Mem. M. C. Z., XXXI, p. 33, Pis. 5, 14, ligs. 1-2. 



Plates 10, figs. 1-9 ; 12^ figs. 7-9. 



In this species there are at least four very distinct sorts of pedicellariae 

 present, of which two may be regarded as large globiferous pedicellariae. 



The normal large globiferous pedicellarios (PL 12'', fig. 7) are of great 

 interest because they are intermediate in character between those which 

 Mortensen considers characteristic of Cldaris, and those which he assigns to 

 Dorocidaris ; thus they are curved and have a large, nearly terminal opening 

 as in the former, but have a powerful end-tooth as in the latter. The valves 

 are about .70 mm. long, and the stalks are about the same length or a little 

 longer. These pedicellariae are found on the abactinal surface, but are not 

 very common. In addition to them, peculiar large pedicellarice (PI. l^** 

 fig. 8) with flat, wide valves, having an inner cavity and a terminal opening, 

 but no end-tooth and no lip, also occur; the valves are about .52 mm. long 

 and nearly .20 wide ; these pedicellariae are found on the actinal surface, 

 especially on the actinostome. 



The tridentate pedicellariae (PI. 12'', fig. 9) have the valves long (1.15 mm.) 

 and slender, considerably separated at the base. They are found mainly on 

 the abactinal surface and appear to be very rare. 



The small globiferous pedicellariae (PI. 10, figs. 1,3) are not peculiar, but 

 have an end-tooth as in Cidaris. The valves are from .19 to .75 mm. in length 

 and their stalks, one or two times as long. They occur everywhere, but are 

 not very common. 



This handsome and very interesting species was collected by the " Alba- 

 tross" during her trip to the Eastern Pacific, in 1904, at the following 

 stations. 



Station 4642. Off southern side of Hood Island, Galapagos. Lat. V 30.5' 

 S.; Long. 89° 35' W. Bott. temp. 48.6°. 300 fathoms. Brk. sh. glob. 



Station 4643. Off southern side of Hood Island, Galapagos. Lat. 

 r 28.7' S.; Long. 89° 48.5' W. Bott. temp. 67.2°. 100 fathoms. Brk. sh. glob. 



Bathymetrical range, 100-300 fathoms. Extremes of temperature, 

 67.2°-47.6°. Twelve specimens. 



