208 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 52 



interpolated division series, the two palmars representing Z^ and Z,, 

 or the first two brachials of the two exterior arms. In nigra the 

 costals and distichals appear both to be interpolated, instead of only 

 the costals, as in the other species ; the proof of this would be found 

 in an arm arising undivided from a distichal axillary (a condition I 

 have not been able to observe, as all the specimens before me have 

 the full complement of palmar series), where, if this interpretation 

 were correct, the first syzygy would be between the third and fourth 

 brachials. This condition, in which a single division series repre- 

 sents internally Z, and Z.,, and externally an interpolated series, I 

 propose to distinguish as compound arm division ; and it seems 

 worth while to recognize the species possessing this compound type 

 of arm division as constituting a distinct genus, which may be desig- 

 nated Comatella, the genotype to be Actinometra nigra P. H. Car- 

 penter. The presence of a syzygy between the first two brachials of 

 the free arm (this being the first syzygy), combined with the exclu- 

 sive occurrence of division series of 2, distinguishes the species at 

 sight from those of the remaining genera. 



COMATELLA NIGRA (P. H. Carpenter) 



Station No. 5136; oil the town of Jolo ; 22 fathoms. 



Station No. 5139; between Jolo and Pangasinan Island; 20 

 fathoms. 



Station No. 5142; north of Jolo town; 21 fathoms. 



Station No. 5145; off Jolo town; 23 fathoms. 



Station No. 5146; west of Tapul Island (south of Jolo); 24 

 fathoms. 



Station No. 5147; off Balinpongpong Island (south of Jolo) ; 21 

 fathoms. 



The cirri are about xx, 30, the distal joints with small dorsal 

 tubercles ; there are three to five post costal axillaries ; the first 

 costals are entirely, and the radials partially, visible; the rays and 

 division series are widely separated. The arms are 150 mm. in 

 length, and the cirri, which are rather stout, 30 mm. 



Family ZYGOMETRID^ 



Genus CaTOPTOMETRA A. H. Clark 



CATOPTOMETRA MAGNIFICA, new species 



Centro-dorsal large, discoidal, with a moderately concave, broad 

 polar area 5 mm. to 10 mm. in diameter, having a deep rounded pit 

 in the center. 



