118 BULLETIN 100, UNITED STATES NATIONAL MUSEUM 
The species name lovenioides might apply equally well to the other 
species of the genus Homolampas, which not only in its general appear- 
ance strongly recalls, but, in my opinion, also actually is closely related 
to Lovenia. 
Genus PALAEOTREMA Koehler 
PALAEOTREMA LOVENI (A. Agassiz) 
Palaeotropus loveni A. AGassiz, Challenger Echinoidea, p. 158, pl. 21, figs. 3-16; 
pl. 39, fig. 88; pl. 41, figs. 28, 29, 1881; Panamic Deep-sea Echini, p. 168, 
pl. 87, 1904.—pe Mertserr, Siboga Echinoidea, p. 200, 1904.—H. L. CLARK, 
Hawaiian and other Pacific Echini, Echinoneidae . . . Spatangidae, p. 153, 
1917 ; Catalogue of the Recent sea-urchins in the British Museum, p. 197, 1925. 
Palaeotrema loveni Koruter, Echinoderma of the Indian Museum, Echinoidea, 
pt. 1, Spatangidés, p. 45, 1914. 
Localities —Station 5183, between Panay and Negros (lat. 10°32’48”" 
N., long. 122°26’ E.); 176 meters; March 30, 1908. Fourteen speci- 
mens, most of them in fair condition. 
Station 5421, between Panay and Guimaras (lat. 10°33’30” N., long. 
122°26’ E.) ; 251 meters; March 30, 1909. Three specimens in poor 
condition. 
Remarks.—These specimens range from 17 to 26 mm. in length of 
the test, the 26 mm. being the largest size hitherto recorded. It is 
then very probable that the species does not reach any larger size, 
and this conclusion is based on a fairly good number of specimens. 
It is noteworthy that only two or three of the Albatross specimens 
are narrower anteriorly than behind, as shown in the Challenger 
Echinoidea, pl. 31, figs. 8, 4, this shape being emphasized by both A. 
Agassiz and H. L. Clark as particularly characteristic of this species; 
the others are regularly oval in outline, or slightly broader in the 
middle. Accordingly, the shape of the test is not a reliable specific 
character, 
Genus PLESIOZONUS de Meijere 
PLESIOZONUS DIOMEDEAE, new species 
Localities —Station 5242 (lat. 6°52’ N., long. 126°14’ E.); 360 
meters; May 14,1908. Fragments of 10 specimens. 
Station 5520 (lat. 8°41’ N., long. 123°18’ E.); 187 meters; August 
10, 1909. Two specimens. 
Type.—uvU.S.N.M. No. E. 7151, from station 5520. 
Description.—In general appearance this species resembles Plesiozo- 
nus hirsutus de Meijere, but it differs markedly from it in several 
important characters. The frontal ambulacrum is somewhat sunken, 
producing a distinct notch at the front edge of the test, which is not 
at all the case in hirsutus, which has the front edge simply rounded. 
The last 1-3 plates of the petals are occluded from the edge of the 
ambulacra ; in hirsutus it is some alternating plates in the distal part 
| 
