PART 5 A MONOGRAPH OF THE EXISTING CRFNOIDS 615 



oms. He said that it is extremely delicate and fragile, and all of the 44 specimens 

 are badly damaged. Not one is approximately whole, but it is possible to determine 

 that large specimens have the disk 3 or 4 mm. across, the arms 90 to 100 mm. long, 

 and the threadlike cirri 25 to 30 mm. long. The color is apparently white or pale 

 yellowish. The holotype (M.C.Z., 1011) is from station 3394 in the Old Bahama 

 Channel off Camaguey, in 200 fathoms. 



Hartlaub's Antedon liarthra undoubtedly belongs to the genus Caryometra, but 

 the specimen from which it was described was so very badly broken as to render its 

 recognition a matter of considerable uncertainty. The columnar arrangement of the 

 cirrus sockets on the centrodorsal is not shown in the drawing (plate 7, figure 8) but is 

 evident hi the photograph (plate 15, figure 1). Hartlaub gives the cirri as about 

 XXXV, and the best preserved PI as 10 mm. long, with 13 segments; the total length 

 of PI was estimated as about 12 to 13 mm. 



From the description and figures there is seen to be a fairly close agreement be- 

 tween Antedon liarthra and Caryometra atlantidis, but the type of the former is larger 

 with the centrodorsal 4.3 mm. in diameter, with more numerous cirri, and with a longer 

 P! which is composed of more numerous segments. It is probable that Antedon liarthra 

 is the same as Caryometra atlantidis, but this is not demonstrable on the evidence at 

 present available. Antedon liarthra was dredged by the Blake at station 262 off Grenada 

 in 92 fathoms in a bottom temperature of 62 F. (16.7 C.). 



Hartlaub described Antedon liarthra as follows: The centrodorsal is conical with a 

 sharp apex and a broad base. The apex of the centrodorsal is free of cirri for a short 

 distance. There are about 35 cirrus sockets which are small, from which it is inferred 

 that the cirri are slender. All the cirri have been lost. 



Only a small portion of the radials is visible. The IBr t are slightly trapezoidal, 

 broader than long; the proximal border is broader than the distal border, and the latter 

 is narrower than the axillary. The distal border has a small vertical elevation which, 

 together with the point of the distal border of the axillary, makes a synarthrial tubercle 

 on the articulation between the two ossicles. The IBr 2 (axillaries) are only a little 

 longer than the IBri, rhombic rather than hexagonal as the lateral edges are short. 

 The IBr[ and the axillaries are entirely free laterally. 



The 10 arms are probably about 90 mm. long. The rather short first brachials 

 are interiorly in contact only by their lower corners. They are somewhat longer 

 exteriorly than interiorly. The second brachials are pentagonal, markedly longer 

 than the first in the median line and with the proximal border produced into a median 

 angle. There is a synarthrial tubercle on the articulation between the first two brach- 

 ials. The first syzygial pair (composed of brachials 3+4) is squarish or often somewhat 

 broader than long. The brachials following are shorter than the syzygial pair and are 

 slightly trapezoidal with somewhat oblique articulations. From the fragments of the 

 arms that have been preserved it may be inferred that the dorsal surface of the brachials 

 is never triangular but remains trapezoidal or bluntly wedge-shaped. Toward the 

 end of the arms the brachials, with the exception of the very long syzygial pairs, appear 

 to be as long as broad. The arms everywhere are entirely smooth. The ambulacral 

 surface of the arms has a rather characteristic appearance as a result of the way in 

 which the musculature is interrupted, in the proximal arm region through fine, in the 

 distal region stronger tongue-shaped or bandlike lateral processes of the brachials 

 which extend inward to the middle of the ambulacral side. 



The first sj'zygy is between brachials 3+4; on an arm preserved as far as the four- 



