A MONOGRAPH OF THE EXISTING CRINOIDS 519 



The cirri are about LXX, 27-30, from 25 to 30 mm. long. 



The 10 IIBr series are 4 (3 + 4). The 20 lIIBr series are 2. The 26 IVBr series 

 are 4 (3 + 4). The 2 VBr series are 2. 



The 68 arms are 130 mm. or shorter and resemble those of the other specimen. 

 All of the arms are grooved. 



Pd is more than 35 mm. long and is composed of more than 80 segments. Teeth 

 are developed from the fortieth or fifty-fifth to the seventy-fifth segments, they 

 being best developed at about the sixtieth segment. The succeeding pinnules to P3 

 decrease in length, but all are provided with combs. 



The disk is 42 mm. in diameter, and the anal funnel is 17 mm. high. 



In one of the specimens from Bock's station 62 the centrodorsal is 11 mm. in 

 diameter, the free dorsal pole being 7 mm. in diameter. 



The cii-ri are about L, 27-32, from 24 to 29 mm. long. A transition segment occurs 

 somewhere between the thirteenth and the eighteenth. 



The IIBr series are 4 (3 +4). The IIIBr series are 2. One of the IVBr series is 2, 

 all the rest being 4 (3 + 4). The single VBr series is 2. 



The 68 arms are from 90 to 110 mm. long. There are 19 brachials for each 10 nmi. 

 of arm length. 



Pd is 32 mm. long, with about 65 segments. Its comb is composed of 10-17 

 indistinct teeth. The pinnule on the IVBr series is 28 mm. long, with about 55 

 segments, of which 12 bear small teeth. P2 is 12 mm. long, with 31 segments, of which 

 8 bear teeth. P3 is 8 mm. long, with 25 segments, of which 5 bear teeth. P4 is 6 mm. 

 long and carries no comb. The genital pinnules are 8.5 mm. long, with about 20 

 segments. The distal pinnules are 11 mm. long, with about 25 segments. 



The disk is 33 mm. in diameter. The mouth is adradial and marginal. The anal 

 tube is somewhat swollen, but is well differentiated from the disk; it is 12 mm. high. 



The color as preserved is brown orange to gray browm. 



Remarks. — The 5 specimens from the Bonin Islands referred to Comantkeria 

 grandicalyx by Gisl6n seem really to represent this species. 



Gislen mentions "very w'eak and indistinct" and "weak but distinct" dorsal 

 spines. These are characteristic of C. imbricaia, but in C. grandicalyx the cirri bear 

 merely low rounded and obscure dorsal humps, m\ich as is the case in Comanthus 

 bennetii. 



The only mention he makes of the distal ends of the brachials is in connection 

 with the specunen from Bock's station 51 in which they are "very swollen, thick, and 

 coarse." This would apply perfectly well to C. imbricata, but would scarcely apply to 

 C. grandicalyx, in which the brachials are almost smooth, with the distal ends only 

 slightly produced. 



It is quite evident that Gislen was led astray by my key to the species of Coman- 

 ihsria in the Siboga report. In this key the cliief emphasis was placed on the assump- 

 tion that the leading feature of C. grandicalyx is the possession of broad division series 

 which are nearly or quite in lateral apposition and of which the component ossicles 

 have smooth distal ends, while in C. imbricata the division series are narrow and 

 strongly convex dorsaliy and the component ossicles have everted and spinous distal 

 ends. 



