258 BULLETIN OF THE 



as long, and bounded without by a gentle curve and within by a deep pointed 

 one. Farther out the plates are more elongated and angular, and soon be- 

 come long diamond-shape. Disk densely beset with short, rounded, pointed 

 spines, which obscure the underlying scales and radial shields. Five flattened, 

 tapering, pointed arm-spines, the two uppermost about as long as one and a 

 half arm -joints, the three lowest somewhat shorter. They are lightly swollen 

 at their base and bear a few minute thorns on their edges. Tentacle-pores 

 large, and furnished with two long, slender spiniform scales, whereof one 

 stands on the side arm-plate, the other on the under one. Color in alcohol, 

 straw. 



Station 148, St. Kitts, 208 fathoms. Station 227, St. Vincent, 573 fath- 

 oms. 



The elongated mouth-angle bearing numerous papillae places this species 

 near 0. stimulea and 0. hirsuta, but it differs much from both those species, 

 especially in the under arm-plates and tentacle-scales. 



Ophiacantha lineolata sp. nov. 



Plate VI. Figs. 79-81. 



Special Marks. — A group of tooth-papillae just under the teeth. Upper 

 surface of disk wholly and thickly set with coarse grains and a few short spines. 

 Eight or nine long, translucent, nearly smooth arm-spines. 



Description of an Individual. — Diameter of disk 18 mm. Length of arm 

 about 135 mm. Width of arm, without spines, 6 mm. At base of mouth- 

 angle, on either side, are three or four rather long papillae, whereof the two 

 outer ones are wider and more flat ; the point of the angle is beset by a cluster 

 of a dozen spine-like papillae which run upward to join the teeth. These last 

 are seven or eight in number, rather narrow, crowded and with a curved cut- 

 ting edge. Mouth-shields heart-shaped with an angle inward ; length to 

 breadth, 2 : 2. Side mouth-shields small, tapering to a point inward, where 

 they meet. Under arm-plates squarish, wider than long, with lateral rides 

 re-enteringly curved and a feeble angle within. Side arm-plates meeting he- 

 low, but not above, and forming a stout, not very prominent spine-crest. Upper 

 arm-plates narrow, four-sided, wider without than within ; length to breadth, 

 1.3 : 1.3. Disk somewhat swollen in interhrachial spaces, thickly set with 

 coarse grains, among which appear a few small spines ; no radial shields 

 visible, their position being granulated like the rest. Genital openings huge 

 and extending ftom mouth-shield to margin of disk. Eighl Ot nine long 

 translucent, nearly smooth arm-spines, decreasing in length from above down- 

 ward ; their cross-section is oval, and it is only on their edges that they have 

 microscopic prickles; length of sppennosl spine 11 mm.; of lowest. -1 mm. 

 One large, oval, pointed tentaole-soale on each pore, except the first, which has 



two. Color in alcohol, pale hrown, with white spines and B white line along 



upper ride of arm. 



