OPHIURANS OF THE PHILIPPINE AND ADJACENT WATERS. 67 

 OPHIOGEMA, new genus. 



Description. — This genus is near the genus Ophiacantha. The 

 dorsal surface of the disk is covered with little plates each bearing 

 a rather stout pointed spine; the distal border of the upper arm 

 plates is also armed with spines resembling those of the disk. Fol- 

 lowing the oral plate, between it and the first under arm plate, there 

 is a supplementary plate which lies on half of the outer border of 

 the adoral plate and carries the outer mouth papilla; this is very 

 much smaller than the following. The under-arm plates are re- 

 markably broadened and short at the commencement of the arms. 

 In the last third of the arms the two first ventral spines show a 

 tendency to become curved towards their tips in such a manner as 

 to direct their points toward the disk, and at the same time they 

 acquire stouter spinules on their concave side without, however, 

 forming a true hook like that seen in Ophientrema leucostictwni, 

 Ophiotreta ?natura, etc. 



The peristomial plates are very large and transversely oval; they 

 recall those which Lyman has represented in Ophiolebes scorteus 

 ('82, pi. 41, fig. 8), but their form is truly oval. 



Type of the genus. — Ophiogema punctata, new species. 



OPHIOGEMA PUNCTATA, new species. 



Plate 29, figs. 7, 8, 9; plate 92, fig. 5. 



Localities. — Albatross station 5166 ; Sulu Archipelago, Tawi Tawi 

 Group; Observation Island bearing N. 20° W., 8.52 kilometers (4.6 

 miles) distant (lat. 4° 56' 10" N., long. 119° 46' 00" E.) ; 177 meters 

 (97 fathoms) ; February 24, 1908 ; co. S. 



Numerous specimens (Cat. Nos. 40989, E. 219, U.S.N.M.). 



Albatross station 5167; Sulu Archipelago, Tawi Tawi Group; 

 Observation Island bearing N. 11° W., 10.4 kilometers (5.6 miles) 

 distant (4° 55' 10" N., long. 119° 45' 30" E.) ; 201 meters (110 

 fathoms) ; February 24, 1908; Co. 



Five specimens (Cat. No. 40990, U.S.N.M.). 



Albatross station 5168; Sulu Archipelago, Tawi Tawi Group; 

 Observation Island bearing N. 17° W., 7.78 kilometers (4.2 miles) 

 distant (lat. 4° 56' 30" N., long. 119° 45' 40" E.) ; 146 meters (80 

 fathoms) ; February 25, 1908. 



Four specimens (Cat. No. 40991, U.S.N.M.). 



Description. — The specimens are none of them large, and the 

 diameter of the disk does not exceed 8 mm. The arms are about 50 

 mm. long. 



The disk is flattened, pentagonal, and more or less excavated in 

 the interradial spaces. The dorsal surface is flat and uniformly 



