96 BULLETIN 100, UNITED STATES NATIONAL MUSEUM 
and ambulacrum (I and) V has 71 pore-pairs in the anterior, 60 in the 
posterior series. There are 3-5 small tubercles on the ridge between 
the consecutive pore-pairs, forming a more or less regular transverse 
series. The outer pore is twice as broad as the inner and is connected 
with the latter by a short, not very deep furrow. The interporiferous 
zone has in the upper part only two, lower down three or four, larger 
tubercles in a transverse series. The ambulacra are about 7 mm. broad 
at the widest, distal part; they continue of the same width to the 
ambitus and on the oral side, narrowing slightly adorally. The 
phyllode is well developed, but not widened, with the three series of 
pores (tube feet) more or less regularly developed. The bourrelets 
are not very prominent. The tubercles of the interambulacra are of 
the same size as those of the ambulacra. The tuberculation of the oral 
side is rather dense. Glassy tubercles are less developed than in @. 
sigsbet and confined to the aboral side. The pedicellariae are not 
specifically characteristic. The spines, of the character usual in 
Echinolampas, aftord no specific features. The color of the spines is 
yellowish, the denuded test whitish. 
On account of the shape of the test this species must be referred to 
the genus Conolampas. From the only species of this genus hitherto 
made known, the West Indian Conolampas sigsbei A. Agassiz, it is 
very well distinguished by the much lower and correspondingly more 
numerous ambulacral plates and by the pores being unequal, the outer 
pore much larger than the inner one (in C@. sigsbei they are of equal 
size) ; also the phyllodes and bourrelets are less developed than in 
C. sigsbei,; on the other hand, the tuberculation of the oral side is much 
denser than in @. stgsbei. It is much more closely related to another 
species of Conolampas than it is to the West Indian species. The 
former was collected by the John Murray Expedition in the Indian 
Ocean, off the Maldive Islands, and is described in my Report on the 
Echinoids of that Expedition, part 2, under the name Conolampas 
murrayana Mortensen. C. diomedeae is distinguished from that 
species mainly by the petals being somewhat longer and narrower and 
by the denser tuberculation of the oral side. 
Order CLYPEASTROIDA 
Family CLYPEASTRIDAE 
Genus CLYPEASTER Lamarck 
CLYPEASTER (STOLONOCLYPUS)! HUMILIS (Leske) 
Clypeaster humilis A. AGAssiz, Revision of the Echini, pp. 100, 510, 1873.—H. L. 
CLARK, Hawaiian and other Pacific Echini: Clypeastridae ... Scutellidae, 
1Concerning the subgenera of Clypeaster reference must be made to the forthcoming 
volume 4, part 2, of my Monograph of the Echinoidea. 
