302 BULLETIN 100, UNITED STATES NATIONAL MUSEUM 



STEREOCIDARIS MICROTUBERCULATA Yoshiwara 



Plates 69, 70 



Cidaris {Stereocidaris) microtuberculata Yoshiwara, Annot. Zool. Jap., vol. 



2, 1898, p. 57; Zool. Mag. Tokyo, vol. 18, 1906, pi. 1, figs. 6, 7. 

 Stereocidaris microtuberculata H. L. Clark, Bull. Mus. Comp. Zool., vol. 



51, No. 7, 1907, p. 220, pis. 1, 2.— A. Agassiz and H. L. Clark, Bull. 



Mus. Comp. Zool., vol. 51, No. 5, 1907, p. 112. 



Localities. — Station 5162; Tawi Tawi group, Jolo (Sulu) Archi- 

 pelago; Tinagta Island (S.) bearing N. 71° W., 5.4 miles distant (lat. 

 5° 10' 00" N., long. 119° 47' 30" E.); 420 meters; bottom temper- 

 ature 11.61° C..J coarse sand and broken shells; February 22, 1908 

 (1 specimen, Cat. Nos. E. 1363, E. 1364, U.S.N.M.). 



Station 5475; east coast of Luzon; San Bernadino Light bearing 

 S. 27° W., 11 miles distant (lat. 12° 55' 25" N., long. 124° 22' 12" 

 E.); 356 meters; bottom temperature 15.17° C; shells; June 24, 

 1909 (1 specimen, Cat. No. E. 1271, U.S.N.M.). 



Notes. — These two specimens differ a little from the typical form 

 from the Sagami Sea in the character of the primaries. While in the 

 three specimens I have seen of the typical form the longitudinal ridges 

 of the primaries are veiy narrow and only very slightly serrate, leaving 

 a rather broad space between them which is covered with a spongy 

 coat of fine anastomosing hairs, the ridges in the present form are 

 broader and more densely serrate; the space between the ridges is 

 thus narrower than in the typical form, but the hair covering is 

 otherwise in the main the same. It is further remarkable that, espe- 

 cially in the larger specimen from station 5475, the ridges are so very 

 much worn as to be scarcely recognizable as such, and the spines 

 look very smooth, almost as if polished; the spines are on the whole 

 very clean. It seems rather puzzling, how they could have become 

 thus worn. 



The primaries of the larger specimen are rather distinctly com- 

 pressed, especially toward the end, which is somewhat widened and 

 obliquely cut, as if they had been used for walking. The primaries 

 are white, slightly darker on the collar. The scrobicular spines and 

 the spines around the anal and the genital openings are of a slight 

 greenish tint; the miliary spines are otherwise of a slight brownish 

 tint. In the second specimen the scrobicular spines do not show any 

 greenish tint; in this specimen a pair of developing apical primaries 

 are of a deep violet tint. 



The primaries are rather long and slender; in the larger specimen, 

 which is 53 mm. in horizontal diameter, the longest spines are 85 mm. 

 in length; in the second specimen, which is 36 mm. in horizontal diam- 

 eter, the spines are up to 63 mm. long. On the latter a specimen of 

 the little synaptid Taeniogyrus cidaridis Ohshima is wound around 

 one of the spines. 



