344 BULLETIN 82, UNITED STATES NATIONAL MUSEUM 



it is usually of the nature of an aggregation of tubercles rather than of a regular pave- 

 ment of plates. 



Prof. F. Jeffrey Bell in 1882 published a specific formula for Antedon granulifera. 

 Early in 1883 this specific formula was emended by Dr. P. H. Carpenter, who pub- 

 lished one also for Antedon brevipinna. 



In 1883 Prof. Ludwig von Graff described the myzostomes found on a specimen 

 on Antedon pourtalesii (nomen nudum) from Blake station 241, repeating this informa- 

 tion in 1884. 



In his report upon the comatulids of the Challenger expedition, published in 1888 

 Dr. Carpenter listed Antedon brevipinna among the species with 10 arms and also among 

 the species with more than 10 arms and the IIBr series 2. He included it in a list of the 

 10-armed species in the Blake collection and remarked that, although normally IIBr 

 2 series are present, they are now and then absent in certain individuals. Antedon 

 brevipinna was included in his key to the species of the Spinifera group, and he gave the 

 range as Straits of Florida in 270 fathoms. This is Corwin station 2, at which only 

 Pourtales' single type specimen was dredged. 



Carpenter included Antedon granulifera in his list of species with more than 10 

 arms with the IIBr series 4(3+4) and the IIIBr series 2(1 +2). He remarked that there 

 is a syzygy between the two elements of the IIIBr series in this species which escaped 

 the notice of Pourtales. He made Antedon granulifera the type of a special group, the 

 Granulifera group including "Tridistichate species with plated ambulacra and the lower 

 parts of the rays flattened laterally." He noted that neither the lateral flattening of 

 the rays, nor the plated disk and ambulacral skeleton of this species, seem to have 

 attracted the attention of Count Pourtales when he examined it, though they have 

 since turned out to be characters of primary systematic value, and called attention to 

 the fact that Pourtales had not noticed the syzygies between the two outer elements 

 of the IIBr series and between the two elements of the IIIBr series; but he said that in 

 neither case is the syzygy at all easy to recognize, and his omission to notice it is there- 

 fore not surprising. He said that in granulifera some of the IIBr series are usually 

 absent, so that the arms spring directly from IBr axillaries, and noted that in arms 

 arising from IBr axillaries the first syzygy is between brachials 3 + 4, while in other arms 

 brachials 1+2 are united by syzygy, and brachials 3+4 may or may not be united by 

 syzygy. He included Antedon granulifera in his key to the species of the Granulifera 

 group in which it was paired with Antedon distincta, the difference given being that in 

 granulifera the lower pinnules are "rather stout," whereas in distincta they are "com- 

 paratively slender." He said that some of the characters of Antedon angusticalyx 

 and A. inaequalis appear in A. granulifera of the Caribbean Sea. Later, under Antedon 

 distincta, he said that this species differs from A. angusticalyx and A. inaequalis in the 

 long interval between the first and second syzygies in the arms, and also in the separa- 

 tion of the IIBr axillaries of adjacent rays by the pinnules on the preceding ossicles, 

 which are attached more toward the dorsal surface than usual. This is less marked in 

 A. granulifera, though it agrees with A. distincta in the long syzygial interval. On 

 I In' other hand, he said, the joints of the genital pinnules of A. distincta are more uni- 

 formly expanded than in A. granulifera, which rather resembles A. angusticalyx. and 

 A. inaequalis in this respect. He noted that A. granulifera seems to be fairly abundant 



