54 S ARGUS OVIS. 



almost black, and the silver colour of the sides of the body quite a dusky-grey. 

 The membrane of the spinous part of the dorsal is semi-transparent, with occa- 

 sional faint tints of palest olive, or bluish-brown ; the spines are white at their 

 tip ; the soft portion is semi-transparent, slightly shaded with dusky-grey ; the 

 pectoral is black at its root only ; the rest is semi-transparent, and in places more 

 or less shaded ; the ventral has the spines and rays of a light colour, and the mem- 

 brane of a bluish tint, almost white behind ; the second anal spine is dirty white, 

 the rays and membrane bluish-black, with occasional lighter tints. 



Dimensions. The head is one fourth of the entire length ; the elevation of the 

 body is rather more than one head and a half, without the dorsal fin, and nearly 

 two heads with it ; total length, two feet. 



Splanchnology. The peritoneum is silvery, pointed with innumerable black dots, so as to give it a 

 dusky tinge. The stomach is rather small, and does not extend more than half the length of the 

 abdomen ; its walls are not very thick ; the pyloric portion begins far back, is narrower than the 

 stomach, and has thicker walls. The small intestine is long, more than twice the length of the 

 body, and makes several convolutions, connected by a loose fold of mesentery. The liver is of 

 moderate size ; the left lobe is the largest, though it does not extend as far back as the stomach ; 

 the transverse portion is thick, and projects backwards to make a kind of third lobe ; the right lobe 

 is smaller, and has a deep fissure between it and the middle portion ; both lobes send pointed pro- 

 longations to the hypochondria, especially the left ; the gall-bladder is long, sub-cylindrical, and 

 convoluted at the place where it terminates in the cystic duct, which is also long and large. The 

 air-bladder is large, and terminates rather broad in front, with a small, short, delicate horn, ascend- 

 ing perpendicularly before the anterior rib ; its walls are remarkably thick and strong ; its inner 

 membrane is very delicate, and can be easily separated from the external ; on its internal and infe- 

 rior face is a large vascular ganglion ; the testicles unite behind, and open into a large cavity ; the 

 ureters unite in one, and thus open into a large urinary bladder. 



Geographical Distribution. The Sargus ovls inhabits the Atlantic shores of 

 America, from Massachusetts, where it has been observed by Dr. Storer, to Cape 

 Florida, where it has been seen by Major Leconte ; from this it ranges along the 

 northern shores of the Gulf of Mexico, even as far west as Lake Pontchartrain, 

 near New Orleans. 



