188 BULLETIN 82, UNITED STATES NATIONAL MUSEUM 



Notes. — After the death of Dr. P. II. Carpenter the Blake collection of comatulids 

 was sent to Dr. Clemens Hartlaub for report. In the collection Hartlaub found three 

 specimens of this species from Blake station 232. Two of these were in the same jar 

 with the label "A. duplex." The third which, in spite of many differences, he regarded 

 as representing the same species, he found with some specimens labeled "A. brevipinna." 

 Hartlaub noted that Carpenter apparently had had more specimens than he had 

 received, for in the Challenger report he had given the bathymetric range as 88-262 

 fathoms. The latter depth was that of a station off Grenada, and also of one in the 

 vicinity of St. Vincent, so that perhaps Carpenter had had specimens from station 249, 

 off Grenada, in 262 fathoms. It is possible, he said, that one of the specimens received 

 by him was from station 249 and that the label had been lost. 



Hartlaub remarked that in the Challenger report Carpenter had placed this species 

 in both the Spinifera and Basicurva groups. 



Hartlaub thus described the two specimens that had been labeled A. duplex by 

 Carpenter. The centrodorsal is subcorneal with strong interradial ridges the ventral 

 ends of which are strongly produced upward in the interradial angles. These inter- 

 radial ridges, each of which is bordered by a column of 4 or 5 cirrus sockets on either 

 side, are well marked. In the midradial line the columns of cirrus sockets are separated 

 by lower ridges so that as a whole the centrodorsal bears 10 ridges, five strong inter- 

 radial and five weaker radial. The moderately rounded dorsal pole is smooth and free 

 of cirri. 



The cirri are about XL, about 50, up to 20 mm. long, and slender. The segments 

 in the proximal half, with the exception of the basal, are somewhat elongated; those in 

 the distal half are uniformly very short and bear small spines on the distal end. The 

 transition from the longer segments in the proximal half of the cirri to the very short 

 segments in the distal half is very abrupt as in Stylometra spinifera. 



The radials are not visible in the larger specimen, though they appear in the 

 smaller. The IB^ are very flat, and in the larger specimen are partially concealed by 

 the centrodorsal. The IBr 2 (axillaries) are short, almost rhombic, and on the proximal 

 border bear a strong process with a sharply set-off base that passes into the pronounced 

 elevation of the IBn, forming a strong synarthrial tubercle. The IIBr series are 2. 

 The IIBr 2 (axillaries) are hexagonal, like the IBr axillaries with a proximally directed 

 process which forms a pronounced articular tubercle with the IIBrj. Single IIIBr 

 series are present in the larger specimen. 



The smaller specimen has 10 arms about 20 mm. long, and the larger has 20 arms 

 about 45 mm. long, though in life it probably had 22. The surface of the arms is smooth. 

 The first 9 or 10 brachials are more or less discoidal and are all short, the first being the 

 shortest. The form of the second brachials is somewhat variable, according to the 

 point of origin of the arm. On arms arising from a IBr axillary the second brachial has 

 more the form of an axillary. The first syzygial pair (composed of brachials 3 + 4) is 

 approximately square. From the tenth onward the brachials are approximately tri- 

 angular. Their proximal and distal ends are arched and have a small sharp lateral 

 point that alternates on succeeding brachials. 



Syzygies occur between brachials 3 + 4, again between brachials 22 + 23, and distally 

 at intervals of 6 muscular articulations. On arms arising from a IBr axillary, on which 



