144 ophionp:reis annulata. 



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

 squarish, a little 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 genu:^ ; triangular, rounded with- 

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

 inner side curv^ed, lateral sides re-enteringly curved, outer corners cleanly 

 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 ; inner side 

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

 l^^ing almost in 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, .8™™'. Arm-spines rounded, tapering, a little flattened, regular ; 

 middle one longest; lengths to that of under arm-plate (twenty-fourth 

 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 dull ash- 

 gray (burnt umlDcr and neutral tint), ground color of arms pale yellow- 

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

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

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

 lines ; a patch of nearly black just outside the mouth-shields ; rest of 

 under surfiice nearly white, w^ith a few under arm-plates brown. 



Variations. — The commonest pattern of color seems to be a purplish- 

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

 rings of purplish brown ; sometimes the disk is white. A young one, 

 with a disk of 3""^, had arms IS.S""""" in length. The upper surfoce 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 Ijetween 

 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 under arm-plates were joroportionately 

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



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

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

 recta. The following table will show their proportions : — 



