239 
The example from Stat, i;^:; is slij4htly smaller than the one just described, with the 
axillaries and brachials proportionately slightly lonj^er. 
One of the individuals from Stat. 251 has the centrodorsal hemispherical, the base 
slightly elongated, the distal border of the radials prominently everted and broken up into five 
or six large rounded bead-like tubercles of which the central one is rather lareer than the 
others, and similar tubercles along the lateral borders of the Ilir, and the outer thirds of the 
contiguous borders of the IBr, and IBr.,. The others, which are smaller, have conical centro- 
dorsals, and plain and unmodified IBr series and lower brachials; owing to the non-development 
of tubercles on the distal angles of the IBrj and beneath the lateral angles of the axillaries 
there are large water pores between the IBr series. 
The specimens from Stat. 254 resemble the smaller individuals from Stat. 251. 
2. Xanouietra bower si (A. H. Clark). 
A. H. Clark. Proc. U. S. National Museum, vol. ^i, 1907, p. 144 [Antcdon viinor; name 
preoccupied); p. 148 (Aiitedon boiversi). 
Smithsonian Miscellaneous Collections (Quarterly Issue), vol. 50, 1907, part 3, p. 341 
[Antfdon orientalis); p. 349 [Xaiiometra minckerti; new name-for Aiitedon minor, preoccupied). 
Proc. U.S. National Museum, vol. 34, 1908, p. 318 (Xanoiiidra boiversi; here considered 
as including Antedon minor and Antedon orientalis). 
5*** Subfamily Isometrinae A. H. Clark. 
The only genus in this subfamily is Isometra, of which a complete account will be found 
in "Die Crinoiden der Antarktis", pp. 145 — 146^). 
6'*' Subfamily H el i o m e t r i n a e .\. II. Clark. 
Key to the Genera of the Subfamil)- Heliometrinae. 
a' 10 radials and 20 arms (coasts of the Antarctic continent, and 
Kerguelen Island; 18 — 400 Metres) Promachocrinus 
a'- 5 radials and 10 arms 
b^ each brachial bears a high median carinate process; Pj much longer 
than P., (c o a s Jt s of the Antarctic co n t i n e n t ; 223 — 400 [? goo] 
Metres) Anthometra 
b- no carinate processes on the brachials 
c' brachials very short, much broader than long; middle and distal 
pinnules with very short segments which are rarely longer than 
broad; cirrus segments very short, only very few, or none at all 
longer than broad; P, and P., of approximately the same length 
(vicinity of Heard Island, and the winter cpiarters 
of the "Discovery"; 135 — 270 Metres) Solanometra 
I) Deutsche Sudpolar-Expedition. vol. l6 (Zoologie, vol. S), May i6, 1915. 
