DOEOCIDARIS CALACANTHA. 13 



are no differences in the abactinal system, except those due to size, and 

 there are four and five primary tubercles. The secondaries occupy nearly 

 the whole of the interambulacral plates outside of the scrobicular area. 

 There are only four actinal interambulacral plates. 



In this smallest specimen the primary spines are stouter and less taper- 

 ing in proportion to the diameter of the test (PI. 14, figs. 1, 5, 6) than in 

 older specimens. 



Only two kinds of pedicellariae occur in this species, as the large 

 globiferous seem to be wholly wanting. 



The tridentate pedicellarice (PI. 4, fig. 3) have the valves very long 

 and slender, and quite abruptly expanded near the base, while the narrow 

 portion is much compressed. The valves are about 1.20 mm. long, and the 

 stalks are of about the same length. These pedicellariae are found mainly 

 on the actinal part of the test. 



The small globiferous pedicellariae (PI. 4, figs. 1, 2) are like those of 

 Heini and hradeata ; the end-tooth is usually very marked. The valves are 

 from .20-.87 mm. long, while the stalks are one to three times as long. 

 They occur everywhere, but the largest ones, on the longest stalks, occur 

 in the scrobicular circles. 



This species we have named calacantha, from the regular and graceful 

 shape of the primary radioles. It was collected by the " Albatross " at the 

 following localities. 



Station 3859. Pailolo Channel, off Mokuhooniki Islet. Bott. temp. 60.2^ 

 138-140 fathoms. Fne. s. m. 



Station 3863. Pailolo Channel, off Mokuhooniki Islet. Bott. temp. 60°. 

 127-154 fathoms. Brk. co. crs. g. r. 



Station 3882. Pailolo Channel, off Mokuhooniki Islet. Bott. temp. 63.5°. 

 136 fathoms. S. co. r. 



Station 3885. Pailolo Channel, off Mokuhooniki Islet. Bott. temp. 

 64.8°. 136-148 fathoms. S. p. 



Station 3886. Pailolo Channel, off Mokuhooniki Islet. Bott. temp. 65'. 

 148 fathoms. P. r. 



Station 4045. West coast of Hawaii. Bott. temp. 49°. 147-198 

 fathoms. Co. s. for. 



Station 4100. Pailolo Channel, off Mokuhooniki Islet. Bott. temp. 61°. 

 130-151 fathoms. Co. s. sh. for. 



Bathymetrical range, 127-198 fiithoms. Extremes of temperature, 65°-49°. 



Twenty-eight specimens. 



