NO. 1559. NEW RECENT UNSTALKED CRINOIDS— CLARK. 7l 



e. Middle and digtal arm joints very short, much wider than long. 

 /. Calyx and arm bases smooth: third syzygy in the twelfth brachial. 

 g. Distal arm joints with smooth edges, not overlapping: intersyzygial 

 interval 1 to 5, usually 3 joints.. (11) ^1. krachijmfro, new species. 

 gg. Distal arm joints strongly overlapping, with serrate edges: inter- 

 syzygial interval 2 joints (9) A.inexpectata, new species. 



ff. Calyx and arm bases spinous: third syzygy in the fourteenth bra- 

 chial (12) J. serratimma, new species. 



ddddd. The third pinnule, while much shorter than the second, has similar 

 joints, which are more elongate than those of the tirst. 

 e. 60 cirrus joints: first pinnule the longest: radials and lower brachials 



with raised and spiny edges (13) A. )ii<irLr, new species. 



ee. 35 to 40 cirrus joints: radials and lower brachials smooth. 



(14) A. liondoensis, new species. 

 bb. Cirri perfectly smooth: distal joints of first pinnule somewhat elongate. 



(15) A. cUo, new species. 



aaa. Lower pinnules long and flagellate, with elongated joints [Tenella group.] 



b. Cirri with more than 30 joints: centrodorsal long and conical with 5 inter- 

 radial ridges, each inclosing 3 rows of cirrus sockets, 

 c. First i>innule much longer than the second. . (16) .1. erytlirlzon, new species. 



cc. Second jtinnule as long as the first (17) A. fragilis, new species. 



bb. Cirri with about 20 joints. 



c. First pinnule twice as long as the second (18) A. tttniis, new species. 



cc. Second pinnule nearly as long as the first. 



d. Middle arm joints triangular : syzygial interval 2 or 3 joints. 

 e. Cirrus joints long: lower pinnules not carinate. 



(19) ,1. ciliata, new species. 

 ce. Cirrus joints short: lower pinnules strongly carinate. 



(21) A. arctica, new species. 

 dd. Middle arm joints quadrate and elongated: syzygial interval 1, sometimes 



2 joints (20) A. ■isis, new species. 



bbb. Cirri with less than 15 joints. 



c. Cirri smooth, with elongated joints : radials and lower brachials in contact 

 and tubercular: first two pinnules short (22) A. briseis, new species. 



I. DECAMETROCRINUS BOREALIS, new species. 



Centro-dorsal eonictil, 1> mm. in diauieter, tuul comparatively high, 

 bearing- about 80 cirri, the dorsal pole free. Cirri lacking-. 



First radials just visible; iirst ])rachial short, about three times as 

 wide as high, somewhat incised by the second; second brachial irreg- 

 ularly quadrate, about as long as wide, with a backward projection, 

 rising into a tubercle; following brachials quadrate, becoming trian- 

 gular after the basal third of the arm. then quadrate again toward the 

 end and elongate at the tip, Syzygies in the fourth brachials, again 

 a))Out the eighth or ninth, and distally at intervals of from 2 to 6 

 (usuall}^ about 3 or 4) joints. Arms 125 nun. in length, with about 100 

 joints. 



First pinnule, on the second brachial, 15 mm. long, slender, with 15 

 or 50 short joints. Second pinnule, on third brachial, 12 mm. long, 

 resembling the tirst; third pinnule like the second; distal pinnules 15 

 mm. long, with about 20 long, slender joints. 



