200 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 52 



Family PENTACRINITID^ 

 Genus METACRINUS P. H. Carpenter 

 METACRINUS ZONATUS, new species 



Stem rather slender, rounded-pentagonal, the lateral grooves 

 slightly marked; internodals 7 to 9 (usually 8), the edges scarcely 

 crenulated, encircled by very prominent ridges, more strongly 

 marked on alternate joints, high and thin, their bases not occupying 

 more than the median third of the joints, and of uniform height all 

 around the stem, passing unchanged over the broadly rounded 

 angles; nodal joints moderately hollowed by the cirrus sockets, and 

 with uniform high thin ridges connecting the bases of the cirri ; 

 cirrus sockets scarcely affecting the supra- and infra-nodal joints. 

 Cirri in length about ten times the diameter of the stem, rather stout 

 basally, composed of 55 to 57 joints, the first five short, then about 

 half again as long as broad, gradually becoming broader than long 

 in the distal half; cirrus joints with rather prominent and finely 

 serrate distal ends, giving them a characteristic feeling and appear- 

 ance. 



Basals broad and of nearly uniform height, slightly convex ex- 

 teriorly, forming a very even basal ring, abruptly cut off distally and 

 not produced into a point; "radials"^ in all instances 8 (2-}- 3; 

 5 + 6) (i. e., "six, the second and fourth syzygies") ; arms dividing 

 three times both exteriorly and interiorly ; distal edges of the arm 

 joints prominent, making the dorsal surface of the skeleton very 

 rough, especially proximal to the last axillary; pinnules resembling 

 those of Metacrinus moseleyi. 



Measurements. — Stem 195 mm. long, with thirty-six internodes; 

 cirri 45 mm. long; arms (from the "primary" radials) 80 mm. long, 

 the terminal 15 mm., with only rudimentary pinnules. 



Another specimen has a stem 190 mm. long, with thirty inter- 

 nodes, and cirri 35 mm. long; the stems of both are freshly broken 

 below. 



Color (in spirits). — Purple; stem, calyx, and arms to the second 

 axillary greenish yellow ; two other specimens are entirely light 

 yellow. 



Type. — Cat. No. 25435, U. S. N. M., from Albatross Station No. 

 5167; off Simonor, Tawi Tawi group; no fathoms. 



' I use Dr. Carpenter's terminology to facilitate comparison with the species 

 described in the Challenger report, in the Linnsean Society's Transactions, and 

 by Dr. Doderlein in the Siboga report. 



