86 BULLETIN 100, UNITED STATES NATIONAL MUSEUM. 



distant (lat. 0° 16' 28" N., long. 121° 33' 30" E.) ; 1,525 meters 

 (834 fathoms) ; November 17, 1909; gn. M. 



One specimen (Cat. No. E. 36, U.S.N.M.). 



Notes. — The specimen is in good condition; the diameter of the 

 disk is 14 mm., and the arms are 70 mm. long. 



In describing O. leucosticta H. L. Clark remarked that this species 

 might belong to a new genus which would be characterized by the 

 incomplete calcification of certain parts of the body and by the 

 peculiar arrangement of the arm spines, as well as of the tentacle 

 scales. But in his memoir of 1915 he places Ophiacantha leucosticta 

 in Verrill's genus Ophientrema with O. scolopendrica. This assign- 

 ment to the genus Ophientrema appears to be perfectly justified, 

 and I shall adopt it here. I believe further that H. L. Clark was 

 perfectly right in removing from the genus Ophientrema O. granu- 

 losa which Verrill thought should be placed with O. scolopendrica; 

 in reality these two species are very different from each other, and 

 if O. scolopendrica be taken as the type of the genus Ophientrema, 

 it is not possible to retain in the same genus O. granulosa. 



The characters to which H. L. Clark drew attention in 1911 and 

 which then seemed to him of such a nature as to justify the creation 

 of a new genus (I am speaking of the reduction of the tentacle pores 

 which occur only on the first arm segments and the arrangement of 

 the arm spines) are shown equally well in O. scolopendrica, and 

 the mouth plates also agree with those of that species; but H. L. 

 Clark's form is remarkable for the incomplete calcification of differ- 

 ent parts of the body, for the form of the upper and under arm 

 plates, and for the characters shown by the ventral spines. 



Another species from Japan described by H. L. Clark in 1911 under 

 the name of Ophiacantha euphylactea ('11, p. 225, fig. 105) seems to 

 me to approach very closely the genus Ophientrema, though without 

 having the characters as well marked as in O. scolopendrica and 

 0. leucosticPu/m. 



My single specimen is a little smaller than H. L. Clark's type, in 

 which the diameter of the disk was 17 mm. and of which the arms 

 were 70 mm. long. Instead of the dark brown coloration of the dorsal 

 surface of the disk which that author described the present specimen 

 has the central portion of the disk olivaceous green ; from this region 

 there diverge five radial bands of the same color, which narrow be- 

 tween the radial shields and do not reach the periphery of the disk, 

 and five interradial bands, which are continued as far as the border 

 of the disk. The intermediate parts, which are chiefly occupied by 

 the radial shields, are a very light yellow, as is also the dorsal surface 

 of the arms. The whole dorsal surface of the disk is studded with 

 little projecting granules, as described by H. L. Clark, of which the 



