FISHES OF MASSACHUSETTS. 189 



edges, and their points are turned outwardly from the centre 

 of the jaw. Branchial orifices five, directly in front of the 

 pectorals. Lateral line, quite high up on the back, and run- 

 ning nearly a straight course to the caudal rays. 



The first Dorsal fin arises from the anterior third of the 

 body ; it is convex before, concave above and behind ; nearly 

 one third higher than long ; arising from its anterior base, and 

 concealed in nearly half of its height by the fin, is seen a 

 strong triangular spine, nearly half the height of the fin. 



The second Dorsal is situated back of the first dorsal, at a 

 distance from it, equal to one fourth the whole length of the 

 fish ; of the same form as the first, but much smaller. A spine, 

 similar in its form and situation with regard to the fin, is seen 

 here as in the first dorsal fin, nearly as high as the fin itself. 



The Pectorals are large, commencing at the last branchial 

 orifice ; their length, less than half their height. 



The Ventrals are small, situated just before the second dor- 

 sal, with the anus between them. 



The Caudal fin is very large and powerful ; its upper portion 

 is broad, and twice the length of the lower portion. 



The young of this species are much more spotted than the 

 adults. A foetus before me, nine inches long, has several 

 white spots on the top of the shoulders ; two in front of, and 

 two just behind the first dorsal fin : also spots on the sides, 

 which, becoming confluent, form a white band extending al- 

 most the whole length of the body. 



Somniosus. Le Sueur. 



Generic characters. Like Spinax they have no spiracles, no 

 anal fins, five small branchial apertures, approximating, and 

 near the pectorals, but they differ in having a short obtuse 

 snout. Pectoral, ventral and dorsal fins very small ; dorsals 

 without spines, caudal as in Spinax. 



S. brevipinna. Le Sueur. The Nurse, or Sleeper. 

 Journal Academy Nat. Sciences, vol. i. p. 222, et fig. 



