418 BULLETIN 100, UNITED STATES NATIONAL MUSEUM. 



tant (lat. 10 37' 30" N., long. 120 11' 05" E.) ; 99 meters (54 

 fathoms) ; April 8, 1909; gn. M., co. S. 



One specimen (Cat. No. 40986, U.S.N.M.). 



Notes. The diameter of the disk varies between 8 mm. and 10 mm. 



In 1904 I described under the name of Ophiomusium sanctum an 

 Ophiomusium which I believed to be new and which did not agree 

 with the description given by Lyman of O. simplex; my specimens 

 were larger than the single individual on which Lyman established 

 this latter species, which had a disk only 6 mm. in diameter. H. L. 

 Clark, who has had at hand a series of 16 specimens in which the 

 diameter of the disk varied between 4 mm. and 14 mm., has been able 

 to convince himself that all intermediate forms between O. simplex 

 Lyman and my O. sanctum exit; it is therefore necessary to unite the 

 two forms (see for further details H. L. Clark's memoir, '11, p. 109). 

 The specimens collected by the Albatross are quite identical with 

 those collected by the Siboga upon which I based O. sanctum in 

 1904. 



OPHIOMUSIUM SPINULOSUM, new species. 



Plate 87, figs. 1-7. 



Localities. Albatross station 5650; Gulf of Boni, Celebes; Lamulu 

 Point bearing N. 5 W., 23.16 kilometers (12.5 miles) distant (lat. 

 4 53' 45" S., long. 121 29' 00" E.) ; 987 meters (540 fathoms) ; 

 December 17, 1909 ; gn. M. 



Two specimens (Cat. No. E. 189, U.S.N.M.). 



Albatross station 5651; Gulf of Boni; Buginkali Point bearing 

 S. 67 E., 38.92 kilometers (21 miles) distant (lat. 4 43' 50" S.", 

 long. 121 23' 24" E.) ; 1,280 meters (700 fathoms) ; December 17, 

 1909. 



One specimen (Cat. No. E. 190, U.S.N.M.). 



Description. The two specimens from station 5650 are complete, 

 and one of them is in an excellent state of preservation ; in the other 

 the disk is somewhat damaged. The diameter of their disks is 

 18 mm., and the arms reach 55 mm. in length. In the specimen from 

 station 5651 the diameter of the disk is 20 mm. ; three arms are 

 broken off at the line of contact with the disk and the two others a 

 little further out. 



I shall describe the species more especially from the specimen 

 from station 5651, which is a little larger than the others. 



The disk is pentagonal, with the borders straight; it is flattened 

 on the two surfaces, which are slightly depressed toward the center. 

 The dorsal surface is covered with very numerous small, subequal, 

 imbricated plates among which it is impossible to recognize the 

 primary plates (fig. 3.) ; but on the two specimens from station 5650 

 (fig. 5) six very small, rounded, and slightly swollen plates may be 



