Opliiuridaj/rom New Zealand. 307 



inouth-sliielJd irri'guhir, narrow, lying along the lower mar- 

 gins of the orals, and not quite meeting within ; mouth- 

 papillai about six to each mouth-angle, three on each side, 

 small, not at all conspicuous ; tooth-papilhe very numerous, 

 arranged in six vertical rows above, gradually diminishing 

 until there are but two series where they meet the teeth ; 

 they extend tar within the mouth, so that the teeth are not 

 visible ; the papilla? of the outer rows are a trifle longer than 

 the intermediate ones, and) increase in size as they approach 

 the teeth, and those at the upper end of tbe tooth-column are 

 very small and irregularly clustering. Teeth 5, subequal, 

 roundly truncated at the ends and thicker in the middle than 

 at their lateral edges. 



Lower arm-plates at the border of the disk about twice as 

 broad as long, gradually becoming proportionally longer as 

 the end of the arm is approached ; their form is irregularly 

 heptagonal, the two sides towards the mouth sloping to a slight 

 pomt ; on the aboral side they are faintly excavated in the 

 middle, and arcuately sloping on each side of this slight sinus 

 towards the lateral margins, which are also concave ; upper 

 arm-plates remarkably flat, twice as broad as long, and gra- 

 dually, like the lower ones, becoming proportionally longer 

 towards the end of the ray ; in form they are transversely 

 oblong, sharply pointed on each side, the points fitting in 

 between the very naiTOw lateral plates ; the latter just meet 

 below between the lower arm-plates, but not quite above ; 

 arm -spines in four series (near the disk sometimes five), the 

 lowest the shortest, the uppermost but one the longest, and 

 the other two about equal in length, but the uppermost one 

 the stoutest ; all the spines are rather flattened, not acutely 

 pointed, and much compressed at the tips and truncated. Above 

 the base of each spine of the uppermost series are two (here 

 and there three) short, broad, compressed spines or scales one 

 upon another, the one nearest the lateral spine the largest and 

 about a fourth its length ; one tentacle-scale, small, roundish ; 

 genital slits two in each interbrachial space, extending from 

 the margin of the disks to the oral shields. 



The colour above is uniformly dull brown, and beneath the 

 rays and ray-spines rather paler. The interbrachial spaces 

 below are dark like the dorsal surface. 



Diameter of the disk about '2G millims. ; width of upper 

 ann-plates 3, of lower ones 2^ ; length of longest spine 5.}. 



Remarks. The form of the mouth-shields is subject to con- 

 siderable variation. In the largest specimen they are almost 

 as long as broad, whilst in a smaller one they are much 

 broader than long. 



