2 BULLETIN 82, UNITED STATES NATIONAL MUSEUM 



Of these Carpenter discarded, for various reasons, Alecto, Comatula, Co-master, 

 and Phanogenia, dividing the 188 species known to him among the remainder in the 

 following proportions : 



Antedon, 122 species. Promachocrinus, 3 species. 



Actinometra, 54 species. Atelecrinus, 3 species. 



Eudiocrinus, 5 species. Thaumatocrinus, 1 species. 



The large number of species hi the genera Antedon and Actinometra as under- 

 stood by Carpenter induced him to group them in small intrageneric units, for which, 

 however, he did not claim subgeneric rank. 



The genus Antedon, on the basis of the type of articulation between the elements 

 of the IBr series, the number of arms, the character of the IIBr series, the character 

 of the proximal brachials, the presence or absence of a highly developed perisomic 

 plating, and the character of the proximal pinnules, he divided into 4 "series," 

 including 10 "groups," as follows: 



Series I: Elegans group. Series III: Spini/era group. 

 Series II: Basicurva group. Palmata group. 



Acoela group. Series IV: Granuli/era group. 



Eschrichti group. Savignyi group. 



Tenella group. 



Milberti group. 



The genus Actinometra, on the basis of the type of articulation between the 

 elements of the IBr series and (or) the first two brachials, the number of arms, the 

 character of the IIBr and subsequent division series, and the position of the lowest 

 pinnule, he divided into 4 "series" and 8 "groups," as follows: 



Series I: Solaris group. Series III: Stelligera group. 



Paucicirra group. Valida group. 



Typica group. Series IV: Fimbriata group. 

 Series II: Echinoptera group. Parvicirra group. 



In 1895 Hartlaub rearranged Carpenter's groups of Antedon in two "series," 

 one containing species with, the other including species without, "plated ambulacra." 

 In 1905 Minckert proposed the genus Decametrocrinus for those species included in 

 Carpenter's genus Promachocrinus in which the arms are undivided. 



Thus when I began work upon the comatulids in 1907, after my return from the 

 North Pacific, I found Carpenter's monograph the standard work and the arrange- 

 ment of the species adopted therein the accepted classification. 



Naturally the earliest papers published after my arrival in Washington contained 

 descriptions of the more extraordinary stalked crinoids brought to light by the investi- 

 gations of the Albatross, since these were very much more easily determined than 

 comatulids, and are of much greater general interest. The first paper (June 15, 

 1907) dealt with Phrynocrinus nudus, the type of a new genus which was made the 

 type of a new family, and with Bathycrinus pacificus, the first species of that genus 

 known from the Pacific, both collected in southern Japan at the end of the preceding 

 August. On the same day there appeared another paper, in which the new genus 



