CENTKOCIDAEIS DOEDERLEINI. 29 



Centrocidaeis 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. iM. C. Z., XXXI, p. 33, Pis. 5, 14, tigs. 1-2. 



Plates 10, fig,s. 1-9 ; 12", figs. 7-9. 



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

 Ijrosent, of which two may be regarded as large globiferous pedicellaria;. 



The normal large globiferous pedicellariaj (PL 12", fig. 7) are of great 

 interest because they are intermediate in character between those which 

 Mortensen considers characteristic of Ckluris, 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 pedicellarite are found on the abactinal surface, but are not 

 very common. In addition to them, peculiar large pedicellaria^ (PI. 12" 

 fig. S) 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 pedicellaria^ are found on the actinal surface, 

 especially on the actinostome. 



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

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

 the abactinal surface and appear to be very rare. 



The small globiferous pedicellarire (PI. 10, figs. 1, .>) 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 hand.some and very interesting species was collected by the '• Alhii 

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

 stations. 



Station 4642. Off southern side of Hood Island, Galapagos. Lat. 1 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. 

 1° 28.7' S.; Long. 89' 48.5' W. Bott. temp. 67.2 . 100 fathoms. Brk. sh. glob. 



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

 67.2°-47.6°. Twelve specimens. 



