32 BULLETIN 100, UNITED STATES NATIONAL MUSEUM. 



their dorsal surface is brownish, and their ventral surface yellow- 

 ish brown. The other specimen is of a general blackish gray. 



As the dorsal surface of the disk of the specimen from station 

 5123 is entirely torn away, I have taken advantage of this oppor- 

 tunity and have prepared the mouthpieces in such a way as to render 

 visible the outlines of the peristomial plates. Their form may be 

 very clearly made out on the photograph which is here reproduced 

 (pi. 3, fig. 7), and it may here be seen that these plates, two in num- 

 ber, are large, quadrangular, almost as long as broad, and in con- 

 tact with each other in the median interradial line. 



Affinities and distinctive features. On the basis of the structure 

 of the dental apparatus, and especially of the characters of the teeth 

 and the dental papillae, this species falls well within the genus 

 Ophiophrixus as it was established by H. L. Clark, which hitherto 

 was represented by only a single species. Ophiophrixus confinis 

 has, like this last, four elongated arm spines, and its radial shields, 

 forming projecting ribs, are armed with very strong spines; the 

 under arm plates are also more or less strongly notched on their 

 distal border; but the new species differs from 0. acanthinus in hav- 

 ing the oral plates much elongated instead of being very low, in 

 the existence of two well developed lateral mouth papillae, and in 

 the absence of distinct plates on the dorsal surface of the disk in 

 its central portion. The type of the genus Ophiophrixus, O. acan- 

 thinus, was found off Japan (Honshu Island) at a depth of 172 to 

 274 meters (94 to 150 fathoms), and is represented only by a single 

 specimen. 



Family TRICHASTERIDAE. 



ASTROCHARIS VIRGO Kcehler. 



Astrocharis virgo KCEHLER ('04), p. 160, pi. 20, fig. 1; pi. 30, fig. 8. H. L. 

 CLABK ('15), p. 178. 



Locality. Albatross station 5423; Jolo Sea; Cagayan Island (S.) 

 bearing S. 11 E., 8.89 kilometers (4.8 miles) distant (lat. 9 38' 30" 

 N., long. 121 11' 00" E.) ; 929 meters (508 fathoms) ; March 31, 

 1909 ;gy. M., co. S. 



One specimen (Cat. No. E. 67, U.S.N.M.). 



Notes. The diameter of the disk is 7 mm. ; the arms are 80 mm. 

 long. 



This specimen agrees well with the type series which was col- 

 lected by the Siboga among the Sunda Islands at depths between 

 522 and 1,089 meters (286 to 595 fathoms). 



I may mention that a second species of this genus, from Sagami 

 Bay, Japan, has been described by Matsumoto under the name of 

 A. ijimai (Matsumoto '15, p. 54, and 17, p. 56). 



