268 BULLETIN 100, UNITED STATES NATIONAL MUSEUM 



the point of the spine. The surface of the shaft is covered with a 

 dense coat of fine anastomosing hairs which end in a long free point. 

 (Fig. 11.) The collar quite short, increasing in thickness downward. 

 The milled ring is very inconspicuous. The apical spines have a 

 well-developed terminal disk which is usually deeply indented on the 

 edge, sometimes very much so, then resembling a delicate flower 

 (pi. 59, fig. 2) ; more rarely the edge is entire. The disk is more or 

 less eccentric, the eccentricity being most developed on the adapical 

 side. In some of the specimens both circles of disks — that is, the 

 uppermost spine in each vertical series — have developed. Sometimes 

 the shaft of these apical spines is fairly long, but in most cases it is 

 short, as is generally the case in Goniocidaris. The basal disk is not 

 developed in these apical spines. The oral primaries are long and 

 slender, distinctly curved, and perfectly smooth, or more rarely with 

 a faint indication of lateral serrations. 



The scrobicular spines are about 3 mm. long, narrow and slender 



and ending in a rounded point; they are flattened and entirely 



o smooth. The marginal ambulacral 



c. o o c= o <£&\>J3^ f spines are about 2 mm. long, very slen- 



^oS^S§S%Oc\ Jo^ ^ er ' an< ^ scarce ^y flattened, those nearest 



f}^!XlT^A^\» > ^ ie peristome being slightly broadened 



toward the point. The miliary spines 

 are slender and pointed. 



Large globiferous pedicellariae were 

 not observed. The small globiferous 

 pedicellariae are fairly numerous, and 



Fig. h.-Part of transverse section i clpnHpr fnmnrp^pH vfllvp^- thp 



of primary spine of goniocidaris nave slender compressed vaives,, tne 

 (Cyrtocidaris) tenuispina, new opening is narrow, more or less elongate, 



and slitlike; the end tooth is usually well 

 developed. (PI. 79, fig. 2-3.). A few large tridentate pedicellariae 

 occur in some of the specimens. These are about 1.5 mm. in length 

 of head, the stalk being much shorter. The valves are rather slender; 

 they have the blade filled, as usual, with a coarse meshwork. 

 (PI. 79, fig. 1.) Although no transitional forms were found and no 

 terminal slit is to be observed in the valves, there can be no doubt 

 that these apparent tridentate pedicellariae are, as in other gonio- 

 cidarids, only a special development of the small globiferous type. 

 (Such transitional forms have been observed in the var. tuberculata.) 



The spicules of the tube feet are of the usual form of irregular 

 slightly spinous rods. The spicules of the intestine are of the tri- 

 radiate type characteristic of goniocidarids. 



The color of the test and of the secondaries is a yellowish white, 

 the denuded test being entirely white. Only in the young specimen 

 from station 5423 is there an indication of green on the apical sys- 



