﻿144 OPHIO^'EEEIS A^^ULATA, 



pointed ; the one next to the outer is the largest of all Teeth five, 

 squarish, a Httle swelled at the cutting edge ; lowest one much shorter 

 than the rest, and somewhat thickened. Mouth-shields nearly rounded, 

 with a slight peak outwards ; length to breadth, 1.4 : 1.4. Side mouth- 

 shields rather larger than usual in this genus ; triangular, rounded with- 

 out, pointed within. Under arm-plates squarish, outer side with a notch, 

 inner side curved, lateral sides re-enteringly curbed, outer comers cleanlv 

 rounded : length to breadth (twenty-second plate), .7 : 1.1. Upper arm- 

 plates wider within than without ■. outer side either forming a single 

 curve, or broken into three sides, an outer and two lateral ; ioner side 

 broken into three parts, an inner and two inner laterals, all of them 

 Iving almost ui the same line ; length to breadth (twenty-ninth plate), 

 .7 : 1.7. Supplementary pieces as long as the joints, triangular, with 

 the outer side somewhat rounded. Disk-scales very fine above and 

 below; coarser along edge of disk; where they are finest, about 170 

 to a square mm. Radial shields small, narrow, sharp at both ends; 

 length, .S""". Arm-spines rounded, tapering, a Uttle flattened, regular ; 

 middle one longest ; lengths to that of under arm-plate ( twenty-foiu"th 

 joint), 1.2, 2.2, 1.6 : .7. Tentacle-scale large, rounded oval ; length to 

 that of under arm-plate. .5 : .7. Color, in alcohol : above, disk duU ash- 

 gray (brnnt umber and neutral tint ), groimd color of arms pale yeUow- 

 ish-grav. with broad bands of dark ash-gray ; even the lighter rings 

 have usually markings of darker ; three joints of Hght usually alternate 

 with three of dark ; below, interbrachial spaces veined with fine brown 

 lines ; a patch of neai'ly black just outside the mouth-shields ; rest of 

 under surface nearly white, with a few imder arm-plates brown. 



Variations. — The commonest pattern of color seems to be a pm^plish- 

 brown disk, with numerous light spots, and light-greenish arms, with 

 rings of pm-jilish brown : sometimes the disk is white. A yoimg' one, 

 with a disk of 3™°, had anus 1-5. o"™' in length. The upper sm-face of 

 the disk was chiefly occupied by the large primary plates, of which 

 there was a rosette of six in the centre, and these did not overlap each 

 other ; other primary plates were arranged about them, and between 

 these were a few small, overlapping scales. The radial shields were 

 separated by three scales, and were larger proportionately than in the 

 adult. The upper arm-plates were nearly circular, the supplementary 

 pieces comparatively small. Below, the parts were pretty much as 

 in the adult, except that the vmder arm-plates were proportionately 

 longer, and the side mouth-shields and interbrachial spaces larger. 



This species has longer arms and sharper spines than O. Xantusii ; 

 and the middle arm-spine is longer than in 0. reticulata, or in 0. jjor- 

 recta. The following table wUl show their proportions : — 



