REPORT ON THE ECHINOIDEA MORTENSEN 251 



Station 5512, vicinity of northern Mindanao; Camp Overton Light 

 bearing S. 76° E., 14 miles distant (lat. 8° 16' 02" N., long. 123° 58' 

 26" E.); 801 meters; bottom temperature 11.56° C; gray mud and 

 fine sand; August 7, 1909 (4 specimens, Cat. No. E. 1366, U.S.N.M.). 



Station 5528; between Bohol and Siquijor; Balicasag Island (C.) 

 bearing N. 15° E., 5.8 miles distant (lat. 9° 24' 45" N., long. 123° 

 39' 15" E.); 790 meters; bottom temperature 11.83° C; globigerina 

 ooze; August 11, 1909 (1 broken test, Cat. No. E. 1261, U.S.N.M.). 



Station 5571; north of Tawi Tawi; Simaluc Island (N.) bearing S. 

 66° E., 5.8 miles distant (lat. 5° 30' 45" N., long. 120° 07' 57" E.) ; 

 612 meters; bottom temperature 11.28° C; sand and shells; Sep- 

 tember 22, 1909 (3 specimens, Cat. No. E. 1385, U.S.N.M.). 



Station 5618; Molucca Passage; March Island bearing S. 69° E., 

 7.8 miles distant (lat. 0° 37' 00" N., long. 127° 15' 00" E.); 750 

 meters; gray mud; November 27, 1909 (1 specimen, Cat. No. E.1296, 

 U.S.N.M.). 



Station 5656; Gulf of Boni, Celebes; Olang Point bearing N. 67° 

 W., 14.5 miles distant (lat. 3° 17' 40" S., long. 120° 36' 45" E.) ; 

 871 meters; gray mud; December 19, 1909 (2 specimens, Cat. Nos. 

 E.1260, E.1284, U.S.N.M.). 



Remarks. — The specimens from station 5571 are too young to be 

 identified with certainty, but in all probability they belong to this 

 species; in any case they are young histocidarids. 



The specimen from station 5618 with the horizontal diameter 38 

 mm. is a very typical H. elegans, its general shape and color and 

 structure of the test and of the spines being in perfect agreement 

 with specimens from the type locality, off Sydney, New South Wales. 

 The pedicellariae are like those of the typical form. (PI. 77, fig. 1.) 

 In the specimen from station 5450, the pedicellariae are of a slightly 

 different shape. (PL 77, fig. 3.) The specimens from stations 5512 

 and 5510 have the typical form of pedicellariae; the former are 

 peculiar in being dark colored on the test and secondary spines; this 

 majr perhaps be due to their having been preserved together with 

 crinoids, the pigment extracted from the crinoids having very often 

 the result of giving specimens of various groups (echinoderms, corals, 

 etc.), an unnatural dark color. Also the large broken specimen from 

 station 5446 has the same dark color (and the same shape of pedicel- 

 lariae). Concerning this latter specimen it is stated on the label 

 "long spines, some of them yellow, others bleaching white; the short 

 spines pale chrome yellow," so that here we have proof that the 

 dark color is not natural and is due in some way to preservation. 



The young specimens from station 5571 deserve special mention. 

 The number of interambulacral plates is 5 ; only the upper tubercles 

 are crenulate. The ambulacral plates on the upper part are 4 or 5 

 to each interambulacral plate, at the peristome only 1 or 2 to an 



