A MONOGRAPH OF THE EXISTING CRINOIDS 243 



In general the proximal pinnules are of delicate structure and are composed of 

 smooth cylindrical segments. P D is about 12 mm. long and is composed of about 25 

 segments of which the basal are moderately thick, those in the distal half are very 

 slender and become toward the end of the pinnule somewhat longer than broad. 

 The segments are dark hi the middle with light-colored ends. P! is similar in appear- 

 ance, about 14 mm. long, and is composed of about 30 segments. It tapers somewhat 

 more gradually than P D . P B is very small. The pinnules following P[ decrease rather 

 abruptly in length to about the thirteenth brachial (P 6 ) and then gradually become 

 longer again, reaching a length of about 10 mm. 



The disk is about 15 mm. in diameter and is deeply incised. In the general dark 

 color of the animal the sacculi are not conspicuous. 



The color is blackish brown. 



Notes. The preceding description is that given by Hartlaub. My notes on the 

 type specimen are as follows: Two cirri still attached to the centrodorsal have 42 

 and 43 segments of which the twelfth and following bear dorsal spines. The longest 

 cirrus segments are not quite so long as broad. In the outer two-thirds, or at least 

 one-half, of the cirri the segments are twice as broad as long. The dorsal spines are 

 rather small and slender, though sharp and prominent. The division series are narrow 

 and rather widely separated. There are 38 arms about 105 mm. long. The brachials 

 are extremely short and discoidal, with produced distal edges. The enlarged proximal 

 pinnules are comparatively slender, and are smooth, not carinate. I remarked that 

 this species appears to be most closely related to H. philiberti but that it is very easily 

 distinguished from that form by the absence of carination on the proximal pinnules and 

 by having the IIIBr series 2 instead of 4 (3+4). 



The specimen dredged by the Alert at Port Molle is small. 



Reichensperger says that the specimen from Dr. H. Merton's station 11 in the 

 Aru Islands agrees almost completely with Hartlaub's description, but it is somewhat 

 larger than the type. The cirri are XXXIII, 40, up to 30 mm. long. All the cirrus 

 segments are longer than broad. Toward the end the cirri become laterally compressed, 

 and from the twelfth to the eighteenth onward the segments bear sharp and prominent 

 dorsal spines. The radials are concealed. The IBr, are free laterally. In the division 

 series the strong preponderance of series with two elements is characteristic. He gives 

 two examples of arm division. On one of these there are two IIBr 4 (3+4) series; one 

 of the latter bears two IIIBr 2 series and a single IVBr 2 series, while the other bears 

 a IIIBr 2 series externally and a IIIBr 4 (3+4) series internally, the latter carrying 

 two IVBr 2 series. In the other example there are two IIBr 4 (3+4) series and four 

 IIIBr 2 series, beyond which there are four IVBr series, the two outer 4 (3+4) 

 and the two inner 2. The 48 arms are 115 mm. long. The first ossicles following each 

 axillary are almost entirely united laterally the result being that the arms are rather 

 close together and often are almost parallel to each other. The dorsal arm sculpture 

 is as figured by Hartlaub. P D is 13 to 14 mm. long and composed of 26 segments of 

 which the first eight are rather thick and markedly broader than long. From the ninth 

 segment onward the pinnule is more flagellate, and finally very slender with segments 

 that are longer than broad. PI, P 2 , and P 3 are of similar structure but are stouter in 

 the distal portion and not so flagellate. P 2 and P 3 decrease rapidly in length and in 

 number of segments. P 4 is only 5 mm. long. The disk is IS mm. in diameter. 



