MUSEUM OF COMPARATIVE ZOOLOGY. 327 



as long, with the end cut square off; the next five thin, narrow, sharp; 

 the innermost one lies under the teeth, and, with its mate from the other 

 side, forms a pair of papillae much stouter than the rest and having a spear- 

 head shape. Tteth five ; the lowest one similar to the pair of mouth-papillae 

 just below it ; the other four flat, rather stout, with a curved cutting e Ige. 

 Mouth-shields broad heart-shape, with a slight peak without ; length to 

 breadth 1.2: 1.5: just along their outer edge, in the interbrachial space, 

 are five or six little spines. Side mouth-shields stout, broader without than 

 within, running along the inner side of the mouth-shield and meeting 

 within ; they enclose the lateral corners of the mouth-shield by a little 

 curved projection. Under arm-plates a little broader than long; bounded 

 without by a clean curve, on the sides by slightly re-entering curves, and 

 within by two curves which meet in a little peak on the median line. Side 

 arm-plates stout, with a prominent ridge for the spines, meeting above and 

 below, even at the first Joint ; they do not, however, encroach much more 

 as they get further out on the arm ; and it is only near the tip that they 

 occupy as much as half of its upper surface. Upper arm- plates broad-tri- 

 angular, the outer side cleanly curved, and the lateral sides straight and 

 meeting within in a sharp point; length to breadth (4th plate) .8 : 1. Disk 

 above beset with rounded, rough grains, mingled with delicate, rounded 

 spines, .8 mm. long, and shaped like those of the arm ; through this cover- 

 ing appear the delicate di^k scales ; and. just over each arm, a pair of short 

 radial shields, of a blunt pear-seed shape ; these are smooth, but are sepa- 

 rated from each other, and from the arm below, by bands of grains and 

 spines; length to breadth 1.5 : 1. In the interbrachial spaces below, the 

 spines and grains are less" numerous. Genital slits large and occupying the 

 full length of the interbrachial space; the edge next the interbrachial 

 space is bounded by the five disk scales. Arm spines seven, all rough, 

 slender, and regularly tapering ; upper ones cylindrical, lower ones, espe- 

 cially the lowest, a little flattened ; lengths to that of the under arm-plate 

 (6th joint) 3.3, 2.5, 2.3, 2.2, 1.8, 1.5, 1 : .8. Tentacle scales large and reg- 

 ularly oval, length .5 mm. Color, in alcohol, disk blue gray, arm yellow 

 gray. A single specimen, off Double-headed Siiot Keys in 315 fathoms. 



Ophioohondrus, gen. nov.* 



Teeth and mouth-papilhe : no tooth-papillae. Disk granulated; con- 

 tracted, so that the interbrachial spaces are re-enteringly curved, and are 

 further much reduced by the encroachment of the stout arms. Side mouth- 

 ids wide and thick and meeting within. Side arm-plates meeting be- 

 low, and there closely soldered so as to form a continuous belt. , Two gen- 

 ital slits in each interbrachial space. 



* 60i?, snake; x°^po;, granule. 



