122 BULLETIN OF THE 



like arm-spine, which is found only on the first two or three joints beyond 

 disk, and stands half-way up the side arm-plate. The second p^ir of mouth- 

 tentacles protrude from very large oval pores covered with four fiat rounded 

 scales ; the next pores, those of the first arm-tentacles, are similar but smaller ; 

 the next still smaller ; whUe those of the fourth under arm-plate are little round 

 holes covered by a single scale. Farther out on arm the pores lie behind and 

 above the rudimentary under arm-plate. Color in alcohol, white. 



The large side arm-plates and few disk-plates suggest that this is a young 

 animal. Unfortunately the depth is given as 18 and 240 fathoms ; but the 

 character of the animal seems to indicate the latter depth. 



Station 172, off Nukualofa, Tongatabu, 18 and 2-iO fathoms, 2 specimens. 



OPHIERNUS * gen. nov. 



Central portion of disk inside radial shields covered by a thick skin ; round 

 the margin a broad band of scaling, interrupted only by radial shields, and cov- 

 ering also the lower interbrachial space, the whole more or less hidden by the 

 skin. Radial shields naked. Teeth, and small, numerous, close-set mouth- 

 papillae. First under arm-plate rather large, and bearing some of the scales of 

 the second paii" of mouth-tentacles. Upper arm-plates covering the whole 

 width of arm. Small smooth arm-spines, arranged along outer edge of side 

 arm-plate. Two large, long genital openings in each interbrachial space. 



In the size and function of the first under arm-plate, and in the size and 

 shape of the upper arm-plates, this genus has a slight relation to Ophioglypha. 



Ophiernus vallinoola sp. nov. 



Plate VI. Figs. 170-17S. 



Special Marks. — Three small cylindrical pointed arm-spines, less than half 

 as long as an arm-joint, set close together and low down on side arm-plate ; 

 mouth-shields rounded and widely separated. 



Descrij)tion of an Individual (Station 78). — Diameter of disk 9 mm. 

 Length of arm about 50 mm. Width of arm close to disk, without spines, 

 1.7 mm. Four small, short, rounded, bead-like mouth-papillae on either side of 

 the mouth-frames, and usually two at apex under teeth, which are four in nunj- 

 her, large and flat, witli a rounded cutting edge ; besides these there are two 

 little papillae on the side month-shield and two on the first under arm-plate, 

 which may be considered scales of the second pair of mouth-tentacles. Mouth- 

 shields triangular, length to breadth about e(]ual, with blunt angle inward, and 

 outer comers rounded. Side mouth-shields short, broad without, pointed 

 within, lying on lateral sides of mouth-shield, by which they seem widely sepa- 

 rated, but the inner narrow points run under the thick skin, and nearly meet 



• 5015, .snake ; (pvo^, sprout. 



