A MONOGRAPH OF THE EXISTING CRINOIDS 293 



tubercular protuberances are also found between the cirri, and on the interradial 

 processes which generally speaking are not especially produced. Here and there small 

 teeth and spines are found also on the first cirrus segments. The cirri are usually 

 arranged in pairs, one above the other. 



The cirri are about XX, 14-18, always much lighter in color than the dark centro- 

 dorsal and division series. The two first segments are short, those following elongated; 

 the antepenultimate bears an opposing spine. 



In ah 1 the specimens the ornamentation of the bases of the postradial series is highly 

 developed and very uniform. Abundantly developed fine dentate protuberances, 

 mostly united into lamellae, cover the flat and more or less concealed IBn, and extend 

 distally along the everted lateral edges of the ossicles as far as the third brachial. In 

 proportion to the degree of their development, the lateral borders of these ossicles 

 acquire a more or less crinkled appearance. The ornamentation of the dorsal surface 

 of the ossicles is exceptionally developed. In addition to the protuberances mentioned, 

 which are distributed over its dorsal surface, the IBri usually bears a few white tubercles 

 among which a median tubercle is usually noticeable because of its greater size. The 

 IBr 2 (axillaries) and the ossicles of the IIBr and IIIBr series bear on the dorsal surface 

 several light colored, often knoblike, tubercles and teeth which in part are coalesced 

 into swellings. In the median line there is a large tubercle, or several which together 

 may form a tubercular longitudinal ridge. On the IIBr axillary and on the IIIBr series 

 and first two brachials, the tubercles often move to the distal edge, which then appears 

 greatly produced. Otherwise the distal and proximal borders of these ossicles are not 

 conspicuously raised, but are usually beset with sharp teeth and spines which are 

 especially well developed at the articulations between the elements of the IBr series. 

 From the IBr axillary to the fourth brachial the ossicles are in very close lateral contact, 

 with sharply flattened sides. Like the centrodorsal, these ossicles are dark colored. 



In all Hartlaub's specimens the radials are entirely concealed, and the mostly 

 concealed IBri are also noteworthy. The IBr 2 (axillaries) are in general flat, more 

 rhombic than pentagonal. Hartlaub noted that the number of the elements in the IIBr 

 series is highly variable, not only in different specimens, but also in a single specimen. 

 Thus the largest specimen, from Blake station 157, has two IIBr 2 series and six IIBr 

 4(3 + 4) series, in one of which there is an uncommonly close union between the first 

 and second elements; two of the arms in this specimen arise from an IBr axillary. 



In another specimen from the same station there are five IIBr 4(3+4) series and 

 three IIBr 2 series. In a third there is one IIBr 1 series (consisting of a single axillary 

 ossicle), four IIBr 2 series, and five IIBr 4(3+4) series. Both IIBr 2 and IIBr 4(3+4) 

 series occur together in the specimen from Blake station 158, and in that from Blake 

 station 34. In the specimen from St. Vincent all the IIBr series present are 4(3+4), 

 but one is missing; this specimen possesses both IIIBr 2 and IIIBr 4(3+4) series. 



In all the specimens the proximal brachials bear an exceedingly characteristic 

 ornamentation. From about the third to about the fifteenth brachial the distal edges 

 are liplike, turned outward and downward. They are not smooth, but slightly tuber- 

 cular or somewhat pleated and markedly overlap the dorsal surface. At the syzygies 

 there are two similar lips close together. 



The disposition of the syzygies is variable, on different arms of the same specimen 

 as well as in different specimens. The first two brachials may be united by syzygy or 



