554 THREE SPECIMENS OF MOLACANTHUS, 



is placed behind the middle of the leugth and above that of 

 the depth. Nostril a small, simple opening in front of the 

 lower part of the eye. Vent very small, placed just below 

 the base of the anal fin. 



Skin closely studded with microscopic scutes, each of which 

 is provided with a more or less distinct central tubercle and 

 radiating striae ; they are somewhat rougher on the ventral 

 surface than on the back, and smoother on the sides. There 

 are twenty-one enlarged spiuiform dermal tubercles, distri- 

 buted as follows: — three on the dorsal profile, of which the 

 median is much the largest, If as long as the eye, and placed 

 in the middle of the back ; another large one on the forehead 

 between the eyes ; three on the ventral profile, the anterior 

 the largest; all the others are paired, and include a very 

 large one below the base of each pectoral, directed outwards 

 and backwards, and another above the postero-superior angle 

 of each eye. Besides these enlarged tubercles, there are other 

 much smaller ones which do not carry spines, and are inter- 

 mediate between the larger ones and the minute scutes ; they 

 are developed evenly on both sides. 



Pectoral with ten rays, the upper the longest, and about 

 If the length of the eye. Normally, the rays are simple and 

 united by membrane, but, when damaged, they split up the 

 middle, so that, without the membrane, they appear to be 

 free, paired filaments. Dorsal and anal fins each with a 

 fleshy base through which the supports for the rays may be 

 seen when examined against the light. The rays are similar 

 to, and about the same length as those of the pectoral, about 

 fourteen in each fin, the outer ones the longest, the others 

 decreasing in length regularly. Caudal with a small triangu- 

 lar fie.shy base covering the support.s for the rays, as in the dor- 

 sal and anal ; there are several, apparently free rays project- 

 ing from it, while other shorter ones are present on the inter- 

 spaces between the dorsal and caudal and anal. 



Colour: — greyish above, changing to whitish below. Pro- 

 bably silvery in life. 



