A MONOGRAPH OF THE EXISTING CRINOIDS 455 



In 1879 Dr. P. H. Carpenter published a long quotation from an unpublished 

 manuscript by Professor Lutken containing descriptions of new species of comatulids. 

 In this manuscript Professor Lutken said: "Moreover the lower or oral pinnules of 

 Actinometra are always very different from the others, being flagelhform and pre- 

 senting a more or less distinct serrature or comb (pinnulae orales prehensiles) ; while 

 in Antedon they are only slightly differentiated from the others, or are transformed 

 into strong rigid spines, forming a protective covering over the disk [A. protectus, 

 mihi]." 



This notice of Antedon protectus identifies it as a species of Stephanometra. The 

 only species of Stephanometra known in the Tonga Islands is the present one, which 

 has been recorded from that region only from specimens that had passed through 

 Liitken's hands. Therefore the Antedon protectus recorded in 1874 and said in 1879 

 to possess strong, rigid, and spinelike pinnules must be this species. 



In his original description of Stephanometra spicata published in 1881 Carpenter 

 said that it is closely allied to the Fijian Antedon protecta Lutken, MS., which has 

 nearly L cirri, smoother brachials, and a relatively smaller P„; but the stiff and pointed 

 lower pinnules are striking features of both species. 



In the Challenger report on the stalked crinoids published in 1884 Carpenter in 

 speaking of the lowest pinnules of the comatulids said that "they may be stiff, straight, 

 and spinelike, as in Antedon protecta." Evidently he here referred to the present 

 species. 



In 1887 in the Challenger report on the myzostomes Prof. Ludwig von Graff 

 listed Antedon marginata from station 208 as a host for myzostomes. The name, 

 which was given him by Carpenter, appears as a nomen nudum. 



In the Challenger report on the comatulids published in 1888 Carpenter described 

 Antedon marginata as a new species. He noted that in the lateral freedom of its divi- 

 sion series and in the presence of irregular processes at their sides marginata resembles 

 tuberculata (= spicata), but he said that it differs from that form in having a smaller 

 number of cirri and no IIIBr series, so that there are only 14 arms instead of 30, 

 while the length of the first pinnules is much more nearly equal in marginata than 

 is the case in tuberculata. 



In the Challenger report Carpenter used the name Antedon protecta Lutken, MS., 

 for a form quite different from that to which he had previously applied it, a minor 

 variety of Lamprometra palmata in which the enlarged oral pinnules are not stiff and 

 spinelike but taper gradually to a more or less delicate tip. He was apparently led 

 into this error through the receipt of a specimen of L. palmata from Prof. Sven Loven 

 that had been labeled Antedon protecta by Professor Lutken. 



In his list of the species of the genus Antedon with their specific formulae "one 

 or two of Professor Liitken's MS. names are included, as they belong to easily recog- 

 nizable types, e. g., Antedon protecta." He listed A. protecta under the formula 

 A. 2. 2., indicating that it is an "Antedon" possessing IIBr 2 and IIIBr 2 series. Further 

 on he said that "in Antedon occulta [ = palmata], and in a large number of similarly 

 bidistichate species, they [the oral pinnules] are stiff and styliform and stand up round 

 the edge of the disk as if to shield it from danger, a character which Lutken has 

 expressed in the specific name Antedon protecta." 



