322 BULLETIN 100, UNITED STATES NATIONAL MUSEUM. 



the increase in the width of the arms were proportional to that of the 

 disk, the arms of an 0. brevipes with the disk 31 mm. in diameter 

 would thus be only 14 mm. broad. I believe, therefore, that this very 

 marked width of the arms constitutes a specific character of con- 

 siderable value. 



Loriol recorded in O. doderleini five arm spines, this figure falling 

 to four at some distance from the base of the arms. In 0. brevipes 

 the number five is quite abnormal, and I have never noticed it in my 

 large specimens from Mauritius; four is the normal number at the 

 base of the arms. These spines are not altogether as described by 

 Loriol; the antepenultimate dorsal spine is the largest, and its length 

 exceeds two segments and a half ; the other spines, which are slightly 

 smaller, are subequal. Generally speaking, these spines are longer 

 than those of O. brevipes, in which the longest reaches only two seg- 

 ments. I shall not consider the annulation of the spines which may 

 be noticed, although very rarely, in O. brevipes. 



I believe, therefore, that O. doderleini should be considered as a 

 species distinct from O. brevipes and that it is necessary to maintain 

 it. It is very unfortunate that my comparison has only been with 

 the single specimen in the Geneva Museum and that I have not been 

 able to compare it with the second known specimen of this species — 

 that collected by the Siboga on the east coast of Borneo — which I 

 recorded in 1905 ('05, p. 60) ; in that specimen the diameter of the 

 disk was only 19 mm. I have very much wished to be able to study 

 this specimen again and to compare it also with O. brevipes, but it 

 was impossible under the circumstances to dream of asking the 

 Leyden Museum for it; I find in my notes only that this specimen 

 agrees absolutely with Loriol's description and figures. 



OPHIOCOMA ERINACEUS Miiller and Troschel. 



Plate 73, fig. 7. 



See for bibliography: 



Ophiocoma scolopendrina, var. erinaceus Kcehler ('05), p. 60; ('07), p. 



326.— Matsttmoto ('17), p. 345. 

 Ophiocoma erinaceus H. L. Clabk ('08), p. 296; ('11), p. 257; ('15), p. 291. 



Localities. — Albatross station 5109; China Sea, off southern Luzon; 

 Corregidor Light bearing N. 42° E., 47.81 kilometers (25.8 miles) 

 distant (lat. 14° 03' 45" N., long. 120° 16' 30" E.) ; 22 meters (12 

 fathoms) ; January 15, 1909; Co. 



Two specimens (Cat. No. 40939, U.S.N.M.). 



Port Binang, Subig Bay; January 9, 1908. 



Two specimens (Cat. No. 40938, U.S.N.M.). 



Notes. — Ophiocoma erinaceus is a well known form which is very 

 widely spread throughout the whole Indo-Paeific region. It is very 



