MUSEUM OF COMPARATIVE ZOOLOGY. 319 



stated that ' >. Grub i was only a variety. I examined specimens of 0. albida 

 dredged by the " Josephine " at the Azores, and they were as different 

 from 0. acercata as those of Scandinavia. 

 Several localities, in from o() to 125 fathoms. 



Opliioglypha falcifera Lyman, sp. now 



ecial Marks. — Three arm-spines, the middle one is a strong hook, 

 turned upwards. Arm-comb single, running along the genital plate and 

 along the outer edge of radial shield, above the arm. 



I: scrij lion of Spt imen. — • D!sk 4.5 mm. Arm 10 mm. Width of arm, 

 1 nun. Mouth-papilla? very short and broad and so closely soldered as to 

 i p; ear like a plain line ; usually, however, there may be distinguished four 

 on each side, of which the two outer are longest; besides these, there is 

 a central, inner one, not soldered with the rest, having a blunt diamond 

 shape, somewhat like the teeth, under which it lies. 



Mouth-shields rounded heart-shape, with a wide curve without, and a de- 

 cided obtuse angle within ; length to breadth 1.1 : .8. Side mouth-shields 

 rather narrow, meeting within, and extending outwards to the lateral cor- 

 ner of the mouth-shield. Under arm-plates, near base of arm, as long as, or 

 longer than, broad; much wider without than within; bounded without by a 

 curve, within by a small angle whose sides are re-entering curves, and on the 

 sides by re-entering curves; a little further out the curves of the inner an«Ie 

 and of the side of the plate are blended in one, and the plate then resem- 

 bles a broad wedge with curved outlines. This wedge widens and shortens 

 as it is found further out on the arm, so that, near the end, it consists of a 

 very obtuse angle without, and of a wavy border within, having a little 

 central peak; length to breadth (4th joint) .4 : .4. Side arm-plates meet- 

 ing everywhere below, and also above, beyond the first joint from the disk. 

 Their line of juncture at the fourth joint is equal to half the length of the 

 under arm-plate ; the total length of the joint being .G mm. This propor- 

 tion rapidly increases, and, near end of arm, this line is double or treble 

 the length of the under arm-plate Upper arm-plates fan-shape, bounded 

 without by a curve and within by two re-entering curves, which meet on the 

 median line; length to breadth .4 : .5. Disk covered above by numerous 

 rounded scales in concentric rows, each row standing higher than that out- 

 side : the central primary plate is highest of all, and has a diameter of .8 mm. 

 Among these are a few smaller, irregular scales. There are three of these 

 concentric circles, whereof the outermost includes the radial shields, which 

 are of a rude pear-seed form, touching near their outer third, so that thev 

 diverge widely within, and less widely without, firming a notch in the disk 

 which includes part of an upper arm-plate ; length to breadth .8 : .8. They 

 are separated within by part of a large scale, which has a rude diamond 



