REPORT ON THE ECHINOIDEA—MORTENSEN 47 
ambulacral tubercles are distinct and form a regular series through- 
out. The interambulacral primary tubercles do not form distinct 
vertical series, and there are no horizontal series on any of the plates. 
The pore pairs are not arranged biserially or in distinct arcs of three. 
The apical system is seen to have been distinctly elongate. The 
peristome is large, 47 percent of the diameter of the test. The gill 
slits are small but fairly sharp. The color of the naked areas is 
reddish, a little darker along the sutures; a narrow dark line sepa- 
rates the naked areas sharply from the whitish tuberculated part of 
the plates. 
Locality—Pangasinan Island, near Jolo (Sulu) ; reef in the south- 
ern part; scattered coral; February 13, 1908. One naked test without 
apical system, probably found on the beach. 
Remarks.—This species recalls to some degree a young Coelopleurus. 
It is very regrettable that only a single naked test of this species 
was found. The characters of the test alone, however, distinguish it 
markedly from all other known recent species of Wicrocyphus. On 
the other hand, it shows a considerable likeness to the fossil Micro- 
cyphus javanus Jeannet from the Miocene of Java, and it is very 
likely that it is the direct descendant of this fossil species. In this 
latter the apical system is not elongate as it is in the recent form, and 
if this be a constant character, which cannot be stated definitely from 
the single known specimen, this will mean that the recent form has 
undergone a remarkable specialization in this regard. 
MICROCYPHUS species 
Note.—The collection includes two naked worn tests lacking the 
apical system, without locality, of some species of Microcyphus. I do 
not think it possible to identify them with certainty as to species. 
Genus MESPILIA L. Agassiz and Desor 
MESPILIA GLOBULUS (Linnaeus) 
Mespilia globulus A. Agassiz, Revision of the Echini, pt. 3 [Mem. Mus. Comp. 
Zool., vol. 3], p. 477, pl. 8a, figs. 18, 14, 1878 —Mortensen, The Danish Expe- 
dition to Siam 1899-1900, II. Echinoidea [Danske Selsk. Skr., ser. 7, vol. 1, 
No. 1], p. 96, pl. 7, figs. 16, 22, 33, 47, 1904.—H. L. CLark, Hawaiian and other 
Pacific Echini, Pedinidae, etc., p. 322, 1912; Catalogue of the recent sea-urchins 
in the British Museum, p. 93, 1925. 
Localities—Station 5159; Tawi Tawi group, Jolo (Sulu) Archi- 
pelago; Tinakta Island (N.) bearing N. 82° W., 1.4 miles distant 
(lat. 5°11’50” N., long. 119°54’00’’ E.); 18 meters; coral sand; 
February 21, 1908. Two specimens. 
Cebu reef; April 4, 1908. One specimen. 
