778 



BULLETIN 82, UNITED STATES NATIONAL MUSEUM 



VOLUME 1 



The distal pinnules have progressively more elongated segments, mostly about 

 four times as long as broad and with slightly expanded joints. 



The larger specimen from station 147 (fig. 49), which is the syntype of abyssorum 

 figured by Carpenter, has the centrodorsal 3.5 mm. in diameter and 1.5 mm. high. 

 The center of the dorsal pole is abruptly raised in a small peak. There are XIX cirrus 

 sockets. 



A fragment of cirrus found in the jar has three very long complete segments, each 

 four times as long as broad, with a broken segment at each end. Carpenter figured a 

 detached cirrus of 7 proximal segments with the first two very short; this fragment is 

 presumably its outer half. 



The 10 arms are all broken within 30 mm. of the calyx. 



The first four brachials measure 4 mm. together and the first syzygy at 4 + 5 is 



1.1 mm. wide. The second brachial is very slightly longer than the first one. It bears 

 the first pinnule on its right side on 8 arms and only twice on the left. 



No P! is complete. 



P a has 25+ segments, the longest of which are only half again as long as broad; 

 it is 8 mm. long. P 2 has 22+ segments, is 8 mm. long and bears a very small gonad ; its 

 longest segments are two to two and a half times as long as broad. All the gonads are 

 much smaller than in the specimen from station 158. 



The smaller specimen from station 147 has the centrodorsal 1.6 mm. in diameter 

 and 1.1 mm. high. It is conical in shape. The first four brachials together measure 



3.2 mm. The second syzygy is either at brachials 9 + 10 or 11 + 12. The pinnules have 

 much longer segments than those of the larger specimens. No gonads are developed. 



There are some small differences between the specimen from station 158 (long. 

 123 E.) and those from station 147 (48 E.), notably the short third cirrus segment of 

 the former (though this is only known from a single cirrus) and the smaller number of 

 segments in the proximal pinnules. It remains to be seen whether these differences are 

 of importance. 



Notes. In the specimen dredged by the Gauss in 2450 meters the centrodorsal is 

 3 mm. in diameter. There are X cirri, and about as many more or less obsolete cirrus 



FIGURE 49. Thaumatocrinur nnovatus P. H. Car- 

 penter, larger syntype of Promachocrinus abys- 

 sorum, B.M., 88.11.9.135-6, Challenger station 

 147. 



m m 



