150 
5- Crotalometra mar spinalis (A. H. Clark). 
A. H. Cl-ARK. Zool. Anzeiger, vol. 39, 1912, W 11,12, p. 424 (Tha/assoinetra inarguialis). 
Stat. 226. Mid-channel between the Lucipara and Schildpad Islands. 1595 Metres. 2 Ex. 
One of the .specimens has 17 arms about 95 mm. long; two of the IIBr series are 2, 
and five are 4(3 + 4); the cirri are 50 mm. long with 60 segments; the other, of the same 
size, has 18 arms with all of the IIBr series 4(3 + 4). 
The individuals have about half the arm and cirrus length of C. rusfica, though 
apparently they represent a species very closely related to it. 
The centrodorsal is low, rounded conical; the cirrus sockets are arranged in columns 
of two each, the two columns in each radial area being in close contact with those of adjacent 
areas exteriorly but separated interiorly by a bare triangular area about half as wide as a 
cirrus socket which comes to a point just beyond the last functional socket and is continued 
thence as a narrow line to the dorsal pole. 
The proximal edge of the IBr^ are produced into a narrow rim which projects over the 
radials, entirely concealing them ; the ends of the basal rays are very prominent as high dorso- 
ventrally elongate tubercles which are usually rather longer than the dorsoventral length of a 
cirrus socket; in the interradial angles the IBrj are cut away to accomodate the basal rays, 
whereas in C. nistica they are separated from the basal rays by the radials which form a 
continuous band all around the calyx. In one specimen a small portion of the lateral edge of 
the radials is visible as two elongate tubercles meeting in a triangle over the ends of the 
basal rays. 
6. Crotalometra magnicirra (Bell). 
Bell. Marine Investigations in South Africa, vol. 3, 1905, p. 141 [Antedon magnicirra); 
p. 142 [Antedon magnicirriis); pi. 4 [Antedon inagnicrinus). 
A. H. Cl.-vkk. Smithsonian Miscellaneous Collections, vol. 61, 1913, N" 15, p. ^^{Crotatometra 
magnicirra). 
Oceanometra A. H. Clark. 
Key to the Species of the Genus Oceanometra. 
a^ Not over 60 cirrus segments; keels on the division series and first two brachials 
confined to the distal element of each pair (axillaries and IIBr^ when not a.xil- 
lary, and second brachials), being entirely absent from the proximal elements; 
large and very robust, the cirri exceptionally stout; 17 arms 180 mm. long; 
cirri XXX, 55 — 60, 60 mm. to 80 mm. long (Hawaiian Islands; 774 — 
858 Metres) gigantea 
a" 62 — 79 cirrus segments; all the elements of the division series and both the 
brachials of the first pair carry keels 
