714 MR. J. Y. JOHNSON ON A NEW SHARK. [JuilC 27 



concave between the eyes and spout-holes ; cheeks convex ; snout 

 short, rounded in front, flat above and below. Nostrils large, reach- 

 ino- to the sides of the snout. Eye-slit ahnond- shaped. Spout-holes 

 transversely oval, placed above the eyes. Mouth wide ; the jaws 

 slightly but evenly convex ; the upper jaw protrusile from beneath 

 the scaly skin. The slit or groove at the commissure advances to 

 the vertical from the middle of the eye, leaving a considerable space 

 between the opposite grooves. The posterior part of the slit is very 

 shallow, and does not extend beyond the vertical from the posterior 

 edge of the spout-holes. 



The teeth of the upper jaw are composed of sharp narrow upright 

 conico-compressed cusps on subquadrate bases ; and several rows of 

 them are in use at once. In the lower jaw there are two rows of 

 teeth, formed of broad flattened cusps on subquadrate bases, which 

 have a ridge down the middle. The cusps, as the teeth approach 

 the back of the mouth, become more and more inclined backwards, 

 but their apices bend upwards and form an acute point ; thus only 

 part of one edge of the cusp presents an incisorial edge, at the 

 middle of the lower jaw, having both its sides in front of the adjacent 

 teeth. It is formed of an upright equilateral cusp with acute edges 

 placed on a quadrate base. 



The five branchial openings are large, and are situate in front of 

 the pectoral fin, the hindmost embracing the anterior part of the root 

 of that fin. 



All the fins are clothed with scales. The first dorsal fin is nearer 

 to the pectoral fin than to the ventral fins, and has in its front part 

 a strong spine more than half as high as the fin, which is so much 

 worn in the specimen that its shape cannot be accurately stated. 

 The second dorsal fin is rounded in front, where it is higher than the 

 anterior fin. It is also armed with a strong spine (which, however, 

 is not quite so large as the spine of ^e first dorsal), and it is acumi- 

 nate behind and prolonged in a dirt^ nearly parallel with the tail. 

 The ventral fins have two-thirds of .we total length of the fish in 

 front of them. Their anterior angles are rounded off, their posterior 

 angles prolonged and pointed. The caur^al fin is sliaped much like 

 that of the true Centrophori. Tiie tail bends upwards inside the 

 upper lobe, and the lower lobe is well developed. The upperside of 

 the tail behind the dorsal fin is concave. The lateral line is high up 

 on the side of the body and straight. The claspers are furnished 

 with a slender spine. 



The scutella or scales are stalked, and have subrotund laminae 

 continuous with their stalks, each lamina being marked by two lateral 

 and a median crest, which projects behind as an equilateral tooth. 

 The hinder edge of the lamina is minutely serrulate. 



The species is named in compliment to Professor Auguste Dumeril 

 of the Jardin des Plantes, Paris, the author of a valuable work 

 describing the known genera and species of Sharks. 



The dimensions of the single example obtained (which has been 

 added to the collection of the British Museum) are given below. 



