130 PROCEEDINGS OP THE ACADEMY OF 



times (18-100) in the head's length ; they are nearly central, the distance 

 from the snout exceeding the height, (two-fifths (43-100) of the length.) 



The nostrils are within the posterior half of the interval between the snout 

 and orbit. The operculum is oblong, and has a somewhat trapezoidal form ; 

 its superior margin advances obliquely upwards ; its posterior snbtruncated 

 and nearly parallel with the preoperculum ; its inferior nearly straight and 

 parallel with the upper margin for half of the length of the operculum, and 

 then curved upwards to the centre of radiation, or from the posterior inferior 

 angle to the angle of radiation, it nearly describes the segment of a circle. 

 Its length above nearly equals four-tenths (39-100), and its greatest exceeds 

 three-tenths (33-100) of the head's length ; its greatest height is less than a 

 fifth (18-100). Its radiating strise and ridges are moderately developed, most 

 distinct and distant on the median and superior surface, and finest most 

 approximated and curved beneath. There are about twenty- four, of which 

 half terminate behind. 



The coalescent inter- and subopercular bones are divided into two portions, 

 an upper and lower ; the upper is nearly equally triangular, with its apex 

 above the articulation of the lower jaw, and its base Innately emarginated and 

 below the operculum ; it has from ten to fourteen radiating strise or slight 

 ridges ; its least diameter, from the apex to the base, equals an eighth of the 

 head's length ; the sides nearly twice as much (23-100). The inferior por- 

 tion is defined above by a straight ridge from the centre of radiation to the 

 end, and scarcely passes beyond the operculum; its greatest length equals 

 tiiree-tenths of the head's ; its surface above is wrinkled parallel with the ob- 

 lique posterior margin, and has slight radiating stria; on its lower half. 



The form of the lower jaw and the dentition offer important characters. 

 The lower jaw forms three-quarters of the head's total length; its superior 

 outline is nearly straight ; its height is somewhat greatest under the second 

 large tooth, but behind is subequal ; its height there equals a tenth of the 

 head's length. 



The teeth of the intermaxillary bones are of normal size, very small, acute 

 and numerous. The large vomerine teeth* are greatly developed and stout ; 

 the curve of the posterior is moderate. The length equals an eighth of the 

 head's, and is three times longer than wide. The posterior or large palatine 

 teeth behind have nearly straight posterior borders. The length nearly equals 

 a twelfth of the head's or three-fourths of the palatine. The smaller teeth 

 behind are contiguous at their bases, oblique, broad and with the posterior 

 margin nearly straight or slightly convex near the base. Each has a median 

 ridge on the surface, which is more distinct towards the tip. There are about 

 nine such teeth. 



The slender and elongated tooth of the front of each branch of the lower 

 jaw is moderately curved ; then follow about twelve slender conical ones ; 

 then three large dagger-shaped ones. The latter are robust ; the posterior 

 margin is at first straight and then slightly curved forwards to the tip ; the 

 posterior tooth has a length equalling half of the hinder vomerine (Go -100), 

 and its width at the base 2\. 



The posterior smaller teeth are broad and contiguous at their bases ; the 

 anterior border is curved very obliquely backwards, and the posterior is 

 nearly straight. There are from thirteen to fifteen. Each one is carinated 

 along the middle. 



Of the dorsal fin, only the roots of the first few rays are not preserved, from 

 which it appears that the first must have originated nearly over the postero- 

 superior angle of the operculum ; the ventrals have been also mostly de- 

 stroyed, but enough is retained to show that there were the usual number of 

 rays, one spinous and twelve-branched. 



* Only the two posterior ones are present in the specimen. 



QMarch, 



