LAMPREYS. 



67 



distinct genus, described under the name Ammoccetes. The lampreys from the sea go 

 up into fresh water in the spring to lay their eggs, travelling mostly at night. Arrived 

 at the proper places, they build up small piles of stones. In the fall the young return 

 to the sea, but it is almost universally believed that the adults die after fulfilling these 

 sexual functions, though this has not been proved beyond a doubt. 



Of the other genera, mention only need be made of Ichthyomyzon, from our west 

 coasts, and Geotria and 3Iordacia, from Chili and the Australian seas. Of the devel- 

 opment of these forms nothing is known ; but from the fact that Ammoccete^like forms 

 occur in the same regions, it is probable that they pass through a metamorphosis like 

 the others. 



Order II. — HYPEROTRETIA. 



Two genera only form the family Myxinid^, the only one in the order Hypero- 

 tretia. These agree in having the nasal aperture communicate with the throat, the 

 mouth small and surrounded with four pairs of barbels, and the number of teeth 

 greatly reduced, there being one on the palate and two rows on the tongue. There 

 may be but a single branchial opening on either side {Myxine), or the number may be 

 much greater, and frequently the number varies on the two sides. The intestine is 

 without a spiral valve. But little is known of the genus Bdellostoma, which contains 

 but three or four species, allfrom the Pacific ; only one, J3. dombeyi, reaching the coast 

 of California. In these foims the number of external branchial openings varies from 

 six to eleven or more on each side, each communicating with its own gill pouch. 

 Myxine (or Gastrobranchus) is somewhat better known, but there are still many 

 points which need investigation in connection with it. On our coast the genus is rep- 

 resented by but a single species, Myxine glutinosa, to which the common names of 

 hag-fish and borer have been applied. The second of these names indicates one of 

 the most marked fieculiarities of these animals. In their distribution they are much 

 like the codfishes, in which they frequently live as internal parasites for a portion of 

 tlieir life. They also attack other fishes in the same way. They attach themselves to 

 the outside of the body, and like the lampreys they scrape away the flesh with their 

 teeth until finally a hole is made through the walls of the body, and they creep into 

 the abdominal cavity. They have the power of secreting slime in almost incredible 

 quantities, a fact to which they owe their generic and specific names. Kept in con- 

 finement for a short time in a small jar of water, they will secrete so much of the 

 mucus as to convert the whole into a mass of jelly. On our coasts they are not very 

 common, though sometimes the fishermen of Eastport and Grand Menan get plenty 

 of them. 



Of the development of the hag-fish nothing is known. The eggs are very large in 

 comparison with the size of the animal, and are covered with a horny case which on 

 either end has a cluster of hooked hairs for adhesion. It would appear from the 

 investigations of Prof. F. W. Putnam that their spawning-time at Eastport was during 

 September or October, or even later in the year. 



J. S. KiNGSLEY. 



