A MONOGRAPH OF THK EXISTING CRXNOIDS 347 



little smaller than specimens from Singapore, with the arms 110 mm. long. The 2 

 IIBr series are 2 (1 + 2). Carpenter noted that in this specimen P,, Pj, and P3 and 

 the corresponding pinnules on the inner side of the arm have strong keels on the 

 lower segments, while there are lesser keels on P4 and P^. He remarked that the 

 same thing occurs in some individuals from Bohol in Semper's collection; it occurs 

 also in others which I have examined from the Philippines. 



The specimen from Banka Strait is small, with the arms about 70 mm. long. 



The specimen from Billiton in the British Museum has moderately stout arms and 

 XV cirri. The one from the same locality recorded by Koehler has 13-15 cirrus seg- 

 ments; the arms are 60 mm. long. 



Of the specimens from Siboga station 49a, 27 are fully grown, with the arms up to 

 about 130 mm. in length, while 31 represent various immature stages. All are more 

 or less pronouncedly of the broad-armed type. One of the fully grown ones is purple, 

 the others being yellow brown. One of the young is orange, the others yellow or 

 yellow browTi. This series closely resembles that from Siboga station 162. 



Two of the specimens from Siboga station 50 have the anterior arms about 110 

 mm. long; another has the anterior arms 90 mm. long and the posterior 60 mm. long, 

 with 4 ungrooved. The last is small. In these individuals the arms are rather 

 slender, with only a suggestion of an approach to the stout type. 



The single specimen from Siboga station 294 is yoimg. 



The specimen from Siboga station 299 has moderately stout arms 115 mm. long. 



The largest specimen from Siboga station 285 has the anterior arms 95 mm. long 

 and the posterior 45 mm. The arms are moderately stout, 6 being grooved and 4 

 ungrooved. The cirri are XIII. A second individual is similar, but slightly smaller. 

 The last is small, wdth the arms about 20 mm. long; the syzygies between the elements 

 of the IBr series and the first 2 brachials are perfectly developed. 



In the specimen from Siboga station 282 the anterior arms are 150 mm. long and 

 the posterior 70 mm. Four of the arms are ungrooved. The arms are very stout, 

 especially the posterior. The cirri are stout and strongly curved, XII, 12-13. 



The specimen from the Malay Archipelago in the Indian Museum is a fine 

 example, with the arms 150 mm. long and the cirri XI, 13-14, 10 mm. long. The 

 arms are slightly swollen in the proximal portion. The one from the Malay Archi- 

 pelago in 292 meters has the arms rather strongly swollen basally, 90 mm. long. 



Linux's original type from the Indian seas was redescribed by A. J. Retzius 

 and by Johannes MuUer. Miiller said that the centrodorsal is concave in the center 

 and the cirri are wholly marginal. The cirri are XVI, 13. The cirrus segments 

 are scarcely higher than broad, and the last bears an opposing spine. The radials 

 are excessively short. The arms are narrower at the base than further out. The 

 brachials are wedge-shaped, the wedges alternating in position. In the mid-lme 

 on the dorsal side they show traces of a keel. The first 4 brachials are united in 2 

 syzygial pairs. The distal intersyz^ygial interval is from 3 to 9 muscular articida- 

 tions. Pi and P. are of equal size. The first 2 segments of P2 are strikingly broadened 

 upward; that is, carinate. P3 is small. The pinnules following are larger and increase 

 rapidly in length. The segments of the pinnules are broader than high. On the 

 dorsal surface of the arms there are very regularly 2 black longitudinal lines which 



