12!) T1IK FHKS1I-WATKK FISHES OF 



The dorsal tins are similar to those of the Sea Lamprey. The first dorsal 

 begins about the middle of the length of the fish ; it is short, and forms a 

 long low triangle, slightly rounded. Its base is one-seventh of the entire 

 length, and it is not so high as the second dorsal which begins at some little 

 distance behind it. The fin rises rapidly to a point and similarly declines 

 posteriorly ; but, before disappearing, merges in the caudal fin, which extends 

 round the extremity of the vertebral column. 



The anal fin is usually but slightly developed ; it is inseparable from the 

 caudal ; and, as a ridge, extends forward to the vent. The dorsal fins have the 

 aspect of adipose fins, but contain branched cartilaginous rays. The vent lies 

 in the last fourth of the length ; the perforated urogenital papilla projects 

 through it. 



The lateral line is not visible. The cephalic canals are indicated by a row 

 of pores behind and over the eye, and extend forward to the upper lip. 



The colour of the back is usually steel-blue, but olive-green in some 

 localities; the sides are yellowish and the belly is silvery-white. The fins 

 are violet. The iris is golden-yellow with a few dark specks. 



The males rarely differ in aspect from the females, but are of rather smaller 

 size. The milt of the male lies in the median line of the body, and is 

 transversely divided into a number of little laminae ; it ends in a point beneath 

 the anterior lobe of the liver. The ovary of the female stretches the entire 

 length of the ventral cavity, terminating opposite the last gill-opening. The 

 intestine is straight, and, as in the Sea Lamprey, has no trace of a stomach. 

 The liver consists of long pointed lobes which lie on the right side. The 

 kidneys in the female are only half as long as the ovaries, but in the male they 

 are as long as the milt. 



The Lampern is limited to low-lying country, and is found in lakes, rivers, 

 and brooks, and marshes, but spawns only where the water runs rapidly over 

 stony bottoms. The spawning takes place in March and April, and then the 

 skin acquires a bright metallic lustre. The eggs are small, one millimetre in 

 diameter, opaquej and of a greyish- yellow colour. After spawning the Lam- 

 pern usually dies. The development of the spawn depends "upon the weather ; 

 and Benecke, who has studied this fish in North Germany, states that in 

 some years only very small broods appear. The young of this species were 

 discovered by August Miiller in 1854, and found to possess distinctive charac- 

 ters, and they have since been bred at Cambridge by artificial fecundation of 

 the eggs by Balfbur and Salvin. The young have no dorsal fin ; the caudal 

 extends much farther forward. The upper lip is expanded into a horse-shoe- 

 shaped hood. The liver possesses a gall-bladder which disappears in the adult 

 Lampern, and the otolites of the auditory capsules are similarly lost in the 



