178 



BULLETIN 75, UNITED STATES NATIONAL MUSEUM. 



presence of which is one of the characteristic features of the genus. 

 Interbrachial spaces below covered with a coat of very fine scales, 

 which are coarsest near the margin. Oral shield longer than wide, 

 pointed within, and rounded distally. Adoral plates very small, 

 lying at the sides of the oral shield. Oral papillae, four or five on a 

 side, thick, bluntly pointed, the next to the outermost largest. Geni- 

 tal slits inconspicuous. First under arm plate rounded; succeeding 

 ones squarish, wider distally than proximall}", scarcely as long as 

 wide, in contact more or less fulh' throughout. Sitle arm plates 

 small, each with three subec{ual, rather slender spines, about as long 

 as a joint. Tentacle scales two or three, one large oval one on side 

 arm plate and one or two very small ones attached to under arm plate. 

 Color (dried from alcohol), variegated greenish-gray and white; the 

 markings of the disk are often very symmetrical, but may be quite 

 irregular; the arms are more or less distinctly banded with a darker 



Fig. so.— Ophiodoris pericalles. x 4. a, from above; 6, from below: c, .side view of three arm 



JOINTS near disk. 



shade of gray. As a rule the radial shields are white and from each 

 one a curved line of white runs inward to the center of the disk. 



Localities. — Albatross station 3740, off Ose Zaki, Honshu Island, 

 Japan, 65 fathoms, volcanic sand, shells, pebbles, 1 specimen; sta- 

 tion 4893, Eastern Sea, hit. 32° 32' N.; long. 128° 32' 50" E., 95 to 

 106 fathoms, gray sand, broken shells, pebbles, bottom temperature 

 55.9°, 2 specimens; station 4894, Eastern Sea, lat. 32° 33' N.; long. 

 128° 32' 10" E., 95 fathoms, gray sand, broken shells, pebbles, 

 bottom temperature 55.9°, 2 specimens; station 4895 Eastern Sea, 

 lat. 32° 33' 10" N.; long. 128° 32' 10" E., 95 fathoms, gray sand, 

 broken shells, pebbles, bottom temperature 55.9°, 4 specimens; sta- 

 tion 4936, Eastern Sea, lat. 30° 54' 40" N.; long. 130° 37' 30" E., 103 

 fathoms, stones, bottom temperature 60.6°, 1 specimen. Bathy- 

 metrical range, 65 to 106 fathoms. Temj)erature range, 60.6° to 

 55.9°. Ten specimens. 



Type.— Cat. No. 25591 U.S.N.M., from station 4894. 



