PART r, A MONOGRAPH OF THE EXISTING CRINOIDS 83 



third again as broad as long, produced posteriorly where they rise into a more or less 

 marked rounded synarthrial tubercle, and with the borders more or less strongly 

 everted. The elements of the IBr series are in lateral contact, but are not laterally 

 flattened. 



The 10 arms are from 55 to 65 mm. long. The first bracliials arc longer exteriorly 

 than interiorly, with the inner edges basally united. The second bracliials arc irreg- 

 ularly quadrate, proximally rising to a synarthrial tubercle. The syzygial pair funned 

 by the third and fourth brachials is about as long as broad. 



The two following brachials are roughly oblong, the succeeding wedgeshaped and 

 then triangular, longer than broad after the ninth, wedgeshaped again at about the 

 middle of the arm, and much elongated and centrally constricted distally. All the 

 brachials have the distal edges strongly everted and finely spinous. 



Syzygies occur between bracliials 3+4, 9 + 10, 14+15, and distally at intervals of 

 3 muscular articulations. 



PI is from 3 to 4 mm. long with 8 to 10 segments of which the first is about as long 

 as broad and the remainder elongated, the third and fourth, which are the longest, 

 being twice as long as broad or longer. P 2 is from 4 to 7 mm. in length, at the base about 

 as stout as PI but becoming almost flagellate distally, with 11 to 13 segments of which 

 the first is broader than long, the second is longer than broad, and the remainder arc- 

 elongated; the outer segments have the distal borders beset with fine spines. P 3 with 

 10 or 11 segments resembles P 2 but is shorter, and P 4 is shorter still and more slender, 

 about as long as PI or even shorter, with about 9 segments of which the fourth to sixth 

 bear a gonad. The following pinnules become more slender and gradually increase in 

 length, the distal pinnules being from 6.5 to 7 mm. long with 15 to 18 segments, of which 

 those beyond the third are from three to four times as long as broad. 



The color in alcohol is (a) white with the perisome and the outer part of the arms 

 light pinkish; (b) light brown with the disk darker; or (c) white, the arms crossed at the 

 second syzygy by a purplish band 2 mm. broad and by two narrower additional purple 

 bands distally. 



Notes. In the type specimen of Toxometra aequipinna the first three pinnules 

 have respectively 8 or 9, 11, and 10 segments, and are 3, 4, and 3.3 mm. long. The 

 arm length is 65 mm. 



A smaller specimen with an arm length of 40 mm. taken with the preceding has 

 the cirri XIV, 10-11, from 4 to 5 mm. long; the synarthrial tubercle between the ele- 

 ments of the IBr series is much less marked. PI is 2.2 mm. long, with S segment-: 

 P 2 is 2.7 mm. long, with 9 or 10 segments; P 3 is 2 mm. long, with 8 segments; P a is 2 mm. 

 long, with (I segments; and the distal pinnules are 5 mm. long. 



This individual was aitaehed to a calcareous sponge. 



[NOTE BY A.M.C.] The Goli.lt n Hind specimen (U.S.N.M., 35694) has been ex- 

 amined by me. It has the low centrodorsal 1.8 mm. in diameter by 1.0 mm. vertical 

 height. The single cirrus remaining is in the second row up from the periphery. It has 

 18 segments, of which the third to fifth are markedly constricted in the middle, this 

 modification gradually disappearing on the following segments. The longest segments 

 are just over half again as long as their median width. The relative length decreases 

 distally so that the three segments before the penultimate are about as wide as long. 

 The cirrus is about 7 mm. long. 



In contrast to the holotype the l-rachials are smooth. 



556-622 67 7 



