100 BULLETIN 82, UNITED STATES NATIONAL MUSEUM 



The cirri are XV-XXXV (usually XX-XXX), 30-56 (usually 36-47), from 25 

 to 40 (usually 30-35) mm. long and are typically rather large and stout. The first 

 four or five segments are broader than long, the fifth-eighth or -tenth are from nearly 

 as long as broad to somewhat longer than broad, being usually about as long as broad, 

 and those following gradually diminish in length, soon becoming markedly broader 

 than long. On the ninth-fourteenth (usually on the tenth or eleventh), which is a 

 more or less evident transition segment, sharp distally directed dorsal spines appear, 

 which reach a length of from one-third to one-half the width of the segments that bear 

 them. The dorsal spines decrease somewhat in size distally. The opposing spine is 

 larger and more prominent than the spines on the segments immediately preceding, 

 and its base occupies the entire dorsal surface of the penultimate segment. The 

 terminal claw is two or three times as long as the penultimate segment and is rather 

 strongly curved. The cirri about the rim of the centrodorsal are about 10 mm. 

 longer than those about the dorsal pole and consist of about 10 more segments, which 

 first bear dorsal spines one or two segments later. 



The distal ends of the radials are just visible beyond the rim of the centrodorsal. 

 The IB^ are short, four times as broad as long or even broader, and are entirely free, 

 or sometimes just in contact, laterally. The IBr 2 (axillaries) are short, broadly 

 pentagonal, not much longer than the IBrj hi the median line. The IIBr series are 

 usually all 4 (3+4), though occasionally 2, and in rare cases as many as half of them 

 may be 2. The IIIBr series are commonly all 2, but more or fewer of them, rarely 

 as many as half, may be 4 (3+4). When IIIBr 4 (3+4) series are developed, they 

 are usually external in reference to the IBr series, as in the genus Himerometra, and 

 occasionally postradial series are found in which the outer IIIBr series are 4 (3 +4) 

 and the inner are 2; rarely most, or even all, of the postradial series are of this 

 character. The IVBr series, when present, are 4 (3+4). They may be developed 

 either on the outermost side of the post-radial series, or on the innermost side of each 

 IIBr series as in Himerometra. The single VBr series reported is 2. The division 

 series are strongly rounded dorsally, and are quite free laterally. The first ossicles 

 immediately following each axillary are interiorly united basally. The elements of 

 the division series and the brachials to about the tenth are markedly smooth and short. 



The arms are 26-80 (usually 35-40) in number and are 70 to 110 (most commonly 

 about 100) mm. long. They are strongly convex dorsally and laterally compressed 

 and are composed of smooth and short brachials, which sometimes are as short as 

 in the genus Himerometra. The distal ends of the brachials usually do not overlap, 

 but often they are slightly produced and very finely spinous. 



The first syzygy is between brachials 3+4, the second is anywhere from between 

 brachials 12 + 13 to between brachials 53+54 (most commonly somewhere near the 

 former position), and the distal intersyzygial interval is 7-21 muscular articulations. 



The elongate proximal pinnules are slender and are often considerably longer on 

 the outermost arms of each postradial series than on the inner. P D is the longest and 

 largest pinnule, varying from rather slender to moderately stout, long and tapering, 

 15-18 mm. long with 27-40 segments of which the basal are moderately stout and the 

 terminal are small. P, is similar to P D but smaller; in one case it is 14 mm. long with 

 3 1-39 segments. P 2 is similar to Pj but smaller, with 32-36 segments. P 3 is 9-12 mm. 

 long with 19-28 segments. P 4 is about 8 mm. long with 18+ segments. P 8 is6mm. 



