/4O STRUCTURE AND DEVELOPMENT OF LEPIDOSTEUS. 



GENERAL DEVELOPMENT. 



The spawning of Lcpidostcus takes place in the neighbour- 

 hood of New York about May 2Oth. Agassiz (No. i) 1 gives an 

 account of the process from Mr S. W. Garman's notes, which we 

 venture to quote in full. 



"Black Lake is well stocked with Bill-fish. When they 

 appear, they are said to come in countless numbers. This is 

 only for a few days in the spring, in the spawning season, between 

 the 1 5th of May and the 8th of June. During the balance of the 

 season they are seldom seen. They remain in the deeper parts 

 of the lake, away from the shore, and, probably, are more or less 

 nocturnal in habits. Out of season, an occasional one is caught 



o 



on a hook baited with a minnow. Commencing with the 2Oth 

 of April, until the I4th of May we were unable to find the Fish, 

 or to find persons who had seen them during this time. Then a 

 fisherman reported having seen one rise to the surface. Later, 

 others were seen. On the afternoon of the iSth, a few were 

 found on the points, depositing the spawn. The temperature at 

 the time was 68 to 69 on the shoals, while out in the lake the 

 mercury stood at 62 to 63. The points on which the eggs were 

 laid were of naked granite, which had been broken by the frost 

 and heat into angular blocks of 3 to 8 inches in diameter. The 

 blocks were tumbled upon each other like loose heaps of brick- 

 bats, and upon and between them the eggs were dropped. The 

 points are the extremities of small capes that make out into the 

 lake. The eggs were laid in water varying in depth from 2 to 

 14 inches. At the time of approaching the shoals, the Fish 

 might be seen to rise quite often to the surface to take air. This 

 they did by thrusting the bill out of the water as far as the 

 corners of the mouth, which was then opened widely and closed 

 with a snap. After taking the air, they seemed more able to 

 remain at the surface. Out in the lake they are very timid, but 

 once buried upon the shoals they become quite reckless as to 

 what is going on about them. A few moments after being driven 



1 The numbers refer to the list of memoirs of the anatomy and development given 

 at the end of this memoir. 



