PART 5 A MONOGRAPH OF THE EXISTING CRINOIDS 665 



flared only on their dorsal sides and to a much lesser extent as well as lacking tlie tliorns. 

 There are no dorsal spines. The segments bej'ond the sixth or seventh arc conspic- 

 uously wider and heavier than the proximal segments. All remain longer than wide. 

 The termmal claw is short; the opposing spine small, with its distal edge convex rather 

 than concave. 



The radials have concave distal edges and so are short in the midline but longer 

 interradially. The IBri are considerably longer and are deeplj' incised by the IBr2 

 (axillaries). Their lateral edges are rounded, not in apposition. The axillaries are 

 about as long as broad, their distal edges strongly concave; the lateral cornei-s are 

 finely thorny. 



The arms were about 20 mm. long. The first brachials are incised by the second 

 ones. The distal edges of all the brachials bej^ond the first syzygy are raised into a 

 row of strong spines, much longer than those of Phrixometra nutrix. Between the first 

 and second syzj'gies the brachials are roughly rectangular, about as long as broad; the 

 distal ones are elongated, roughly oblong. The pro.ximal syzygies are between the 

 usual brachials, distally they occur at intervals of two muscular articulations. 



The first segment of all the pinnules is short, the second as long as or a little longer 

 than broad. The rest are elongated and somewhat constricted in the middle, the 

 distal ones more markedly so than the proximal; the distal edge of each is expanded 

 into a wide spiny flare around the base of the next, giving the joints a swollen appearance. 

 Pi has 11 to 12 segments, about 3 mm. long. P2 has 13 to 14 segments, about 4 mm. 

 long. P3 is the fu-st genital pinnule and is shorter than P2; it has 9 segments, about 

 3 mm. long. There are only three pairs of genital pinnides, all similar to P3. The 

 long yellow gonad lies along the third to sixth segments. The specimen is a male. 

 P5 is tlie first pinnule to have an ambulacral furrow. The outer pinnules have up to 

 14 or 15 segments, 4 to 5 mm. long. 



The disk cannot be seen in the type specimen. The anal cone seems to bo high. 



The sacculi are fairly conspicuous, irregularly arranged along the genital pinnules, 

 regularly along the outer. 



There are no side or cover plates along the ambulacra of the distal pinnules, nor 

 any spicules in the tentacles. 



Locality. — Discovery Investigations station 160, near Shag Rocks, west from 

 South Georgia (lat. 53°43'40" S., long. 40°o7' W.); 177 meters; at 170 meters, tem- 

 perature 1.42° C, salinity 34.22%o; gray mud, stones and rock; February 2, 1927 

 [John, 1938] (1, B.M.). 



Genus BOLEOMETRA A. H. Clark 



Antedon (part) A. H. Clark, Proc. U.S. Nat. Mus., vol. 33, 1907, p. 79. 



Heliomeira (part) A. H. Cl.\rk, Smithsonian Misc. Coll., vol. 50, pt. 3, 1907, p. 351. 



Cydometra (part) A. H. Clark, Proc. Biol. Soc. Washington, vol. 24, 1911, p. 88. — Gisl^n, Vid. 



Medd. Nat. Foren. Iv0benhavn, vol. 83, 1927, p. 51. 

 Boleometra A. H. Clark, Proc. U.S. Nat. Mus., vol. 83, 1936, p. 2-18 (diagnosis; type species Antedon 



Clio A. H. Clark, 1907). 



Diagnosis. — A genus of Bath_\Tnetrinae in which Pi has about 30 segments, the 

 first 5 to 7 of which are as broad as, or broader than, long; there are not more than 

 30 cirrus segments of which the distal ones are not longer than broad; the brachials and 



