A MONOGRAPH OF THE EXISTING CRINOIDS 199 



proximal brachials are discoidal and have smooth articulations. The first brachial 

 syzygy is between brachials 3+4, the second is at about brachials 24+25, and the 

 distal intersyzygial interval is usually 9 muscular articulations. 



P D and P P are thick and massive. P D is about 13 mm. long and is composed of 

 about 18 approximately squarish segments which gradually become somewhat more 

 slender toward the end of the pinnule. P P is of the same form and sometimes also of 

 almost the same length. PI on the outer arms has a similar form at the base but it 

 is much shorter and after the basal segments quickly becomes slender. On the inner 

 arms PI is markedly weaker. P a is extraordinarily small. The following pinnule 

 pairs, especially from the third onward, are very small and are of about the same 

 length. From the fifteenth brachial onward they very gradually become larger 

 though they do not reach more than 5 mm. in length. The sacculi on the pinnules 

 are small and scattered. The disk is lacking. 



Hartlaub said that this specimen is unfortunately much broken, the cirri and 

 most of the arms having been lost. He said that the species represented is remarkable 

 for the thickness of the proximal pinnules, which is the more noticeable as the more 

 distal pinnules are unusually small and slender. He regarded the shortness and rapid 

 taper of the arms as noteworthy, this being in contrast to the central portion of the 

 animal which has a stout centrodorsal and relatively strong first division series. He 

 said that the new species seems to stand nearest to Antedon (Himerometra} martensi 

 from which it differs, however, in the form of the centrodorsal, the arms, and the lower 

 pinnules. The last are very massive in both species, but more so in martensi in which 

 there is a special enlargement of the basal segments. Besides, in martensi the thick 

 pinnules have an uneven surface due to the abrupt decrease in the size of their com- 

 ponent segments, which is not the case in kraepelini. Also in martensi the strong 

 production of the distal border of the brachials begins at the third brachial. 



When at Hamburg in 1910 I examined this specimen. It appears to be a small 

 specimen of robustipinna (that is, the form which I described as robustipinna in 1908) 

 with which it agrees in the absence of a thickening or eversion of the distal ends of the 

 segments of the enlarged proximal pinnules. The lack of the pinnule tips and of the 

 cirri prevent a wholly satisfactory determination. 



Under the name of Himerometra kraepelini Reichensperger recorded two well- 

 preserved specimens from Ceylon. In the larger individual the centrodorsal is thick 

 with a large concave dorsal pole. The cirri are arranged in two rows. The cirri are 

 XXX, 25-30, from 27.5 to 35 mm. long. The first four or five segments are markedly 

 broader than long, and that following is about as long as broad; the next five or six 

 are somewhat longer than broad, but toward the end of the cirri the segments become 

 again markedly broader than long. There are no dorsal spines, but the last three or 

 four segments bear a very faint dorsal swelling. The antepenultimate segment has 

 a small blunt spine. The terminal claw is short and curved. There are 46 arms 95 

 mm. long. There are up to four divisions. In their structure the arms agree com- 

 pletely with Hartlaub's description. The basal portion of the arms is smooth. From 

 the last division onward the arms taper rapidly and are very rough with entirely 

 discoidal brachials. P D is the thickest and longest pinnule, stiff, the easily broken 

 point turned somewhat outward. It is 14-15 mm. long and is composed of 14-18 

 segments, all of which are more or less squarish. The distal ends never overlap. 



