148 Bulletin American Museum of Natural History [Vol. XLVIII 



Crinoidea 

 Trichometra europacifica, new species 



Centro-dorsal relatively large, conical, covered by the cirrus sockets, which are 

 arranged in about three horizontal series, no vertical series or radial groups being 

 indicated. 



Cirri about 20 in number, 4 or 5 mm. long, with 15 or 16 segments. The cirri 

 at the apex of the centro-dorsal are noticeably smaller than those in the outer or 

 marginal series. Basal segment almost discoidal, its length not one-half its thickness; 

 second segment not quite so long as wide; third, distinctly longer than its distal 

 diameter, which is greater than the proximal; fourth segment the longest of all, 

 twice as long as the distal diameter, which is much greater than the proximal; the 

 segment is nearly cylindrical where its diameter is least, proximal to the middle; 

 the distal margin is flaring, especially on the dorsal side, where it projects consider- 

 ably. Fifth segment very similar to fourth, but sixth and seventh are shorter and 

 stouter. Succeeding segments each a trifle shorter and smaller than its predecessor, 

 and the least diameter is at the proximal margin more and more clearly. But even 

 the fifteenth and sixteenth segments are longer than their distal diameter. Sixteenth 

 segment with a conspicuous opposing spine which is not quite so long as the diameter 

 of the segment. Terminal claw moderately slender, slightly curved, about equal to 

 the last segment in length. 



Radials almost bowl-shaped, the width nearly three times the length in the 

 median line, which is somewhat less than the lateral margins, as the distal margin is 

 distinctly concave. The first costals are similar to the radials but are lower, the width 

 being fully three times the length. Costal axillaries rhombic, about as long as broad, 

 the margins slightly concave, the angles blunt and rounded; the anterior margins 

 are swollen, flaring and a little roughened. Surface of all the I Br series otherwise 

 quite smooth. Costals and axillaries scarcely in contact, but first brachials externally 

 appressed; hence there is a distinct pit-like depression between the I Br series of 

 adjoining radii. 



Ten arms, all broken distally so the length can only be estimated; probably 

 about 25 mm. long. First brachial short, its outer edge about twice as long as inner, 

 its distal margin only a little concave and not at all flaring, and nearly smooth; second 

 brachial irregularly pentagonal, about as long as thick; third and fourth brachials, 

 united by syzygy, together longer than the second and therefore distinctly longer than 

 broad; following brachials about as long as broad, except syzygial pairs, which dis- 

 tally probably occur at intervals of two bifascial articulations. Beyond the third 

 brachial, the distal margin of each pinnule-bearing segment projects as a spiny knob, 

 characteristic of the genus, but these knobs are not conspicuous and are best seen in a 

 perfectly profile view of a dried arm; when thus viewed the dorsal median line of each 

 brachial is distinctly concave. 



Pinnules all broken and defective, but enough segments are left to show that all 

 were very slender and distally filiform. In the first pinnule the basal joint is about as 

 long as wide, the second is longer, the third still longer and the fourth is fully twice as 

 long as thick. The distal segments on all the pinnules are extremely slender at middle, 

 but conspicuously swollen at the joints. Genital glands are present on some of the 

 basal pinnules. 



Color very pale brown dorsally, the cirri nearly white; oral surface dark brown. 



Type.— Cat. No. — , U. S. Nat. Mus., from Station 5692. 



