MICROPOGON UNDULATUS. 147 



Colour. The head is rather dusky above ; the lower jaw and cheeks are white ; 

 the entire body is silvery, slightly shaded above, and marked with numerous and 

 irregular dusky spots, in general disposed without order, though rarely they are 

 confluent and represent interrupted lines ; these dusky spots disappear below the 

 plane of the pectoral fin, and leave the belly white. The spinous portion of the 

 dorsal is semi-transparent above, while below there are two or three irregular 

 series of dusky blotches in the membrane that unites the spines ; the soft portion 

 is semi-transparent above, but with several rows of dusky blotches below ; that 

 near the roots of the rays is very regular ; the pectoral is transparent, being only 

 dark at its root ; the ventral is yellow on its outer part, and white on its inner ; 

 the spine of the anal is white ; the four rays next to it are yellow, most so at their 

 tips ; the others are white or transparent. 



Dimensions. The distance between the opercle and the tip of the tail is equal 

 to two heads and three quarters; the elevation is not quite a head in any one 

 part ; total length, fourteen inches. 



Splanchnology. The liver is very small, though the transverse portion is thick and projecting ; the 

 left lobe is longest, and extends back about two thirds the length of the abdomen ; the right is 

 swollen in front, and is about half as long as the left ; and both project into the hypochondria. 

 Tile gall-bladder is large, elongated, cylindrical, and runs farther back than the lobe to which it is 

 attached. The stomach is of moderate size, conical, with thick walls, and ends behind with the 

 left lobe of the liver. The pyloric portion is small, short, separating from the stomach far forward 

 and at right angles. There are six delicate ccecal appendages, nearly all of the same calibre, but 

 varying much in length ; some being nearly half as long as the stomach. The small intestine is 

 large ; it runs to the vent, thence returns to the beginning of the pyloric portion of the stomach, 

 whence it is reflected to end in the rectum, which is smaller, but with much thicker walls and a 

 very well developed rectal valve. The spleen is small, but elongated, flattened, and does not ex- 

 tend behind the stomach. The testicles are oblong, narrow, pointed in front, and unite in substance 

 far behind. The air-bladder is large, broad, sub-round ; it is largest in front, and tapers to a point 

 behind ; on each side, and a little anterior to its middle, arises a delicate, slender horn, which runs 

 forward, and, having passed its anterior extremity, curves inward, so as nearly to meet its fellow at 

 a considerable distance in front of the organ itself; there are muscular fibres on the inferior and 

 posterior portion of the air-bladder. The kidney is broad before, but narrow along the middle of 



