THE HICKORY SHAD. 607 



observed to eat, and a few days later they were all vigorously engaged in pursuit of food. 

 While the ratio of mortality was large, some of the fish survived for six weeks, the last specimen 

 having attained a length of considerably more than an inch, and a weight many times greater 

 than that at birth. 



From these experiments we deem it altogether probable that under natural conditions the 

 Copepoda, which are abundant in the Potomac in places frequented by the young Shad, are their 

 natural food during the early stages of their existence. Although we are able to obtain from the 

 river late in the season young Shad which are two and a half to three, and a half inches in 

 length, I ani not aware that such examinations have been made upon the contents of their 

 stomachs as to show the character of their food. In order to take observations upon the food 

 of the Shad at the stages indicated above, I procured from the Potomac a number of young 

 Shad, two to three inches in length, which were placed in the basin under the dome of the United 

 States National Museum. These were tempted with various kinds of food; oysters, liver, stur- 

 geon, and beef finely chopped were offered successively to them, but they declined to take the food. 

 In some cases they would seize particles, which having held for an instant, they would eject 

 from their mouths with evident expression of disgust. I then tried them with the white of hard- 

 boiled eggs. This, much to niy gratification, they devoured readily. As soon as the particles 

 reached the surface of the water, the fish rose vigorously and seized them as they sank through 

 the water, but, strange to say, in no case did I observe them take the food after it had touched 

 the bottom. This would seem to show that their food under natural circumstances is taken 

 swimming, and consists probably of swimming crustaceans, or allied forms of life found in salt 

 water. Later in the season, in consequence of my absence from the city, these fish were neg- 

 lected and fed irregularly. By way of experiment, I had also placed in this basin a number of 

 young California salmon, and, to my surprise, I discovered that the young Shad were pursuing 

 and eating them. In several cases I noticed the Shad with the salmon in their mouths half 

 swallowed. Finally the salmon disappeared, and the presumption was that they had all been 

 eaten by the young Shad. It is possible, therefore, that Shad in their early lives vary then- 

 food with minnows and the young of other species of fish. Indeed, from the stomach of a Shad, 

 taken in ore of the pounds at Saybrook, I found an undigested minnow two or three inches in 

 length. In the fresh-water life of the mature Shad, the fish do not seem to take food at all. 

 Repeated observations of the contents of the stomach show no food whatever. Occasionally, 

 however, they can be. induced to rise to a fly dexterously cast on the water. This fact is pre- 

 sumptive evidence that the. desire for food, although subordinated to the impulse of reproduction 

 (which brings them into the river), is not wholly lost. 



180. THE HICKORY SHAD, OR MATTOWACCA-CLUPEA MEDIOCRIS. 

 H.v MARSHALL MCDONALD. 



. NAMES. This fish, C. mefliocris, Mitchill, was h'rst brought to notice in 1815 in Mite-hill's paper 

 on the lishes of New York, wherein it was described under two names, being called the "Statcn 

 Island" Herring, C. mediocriit, and the "Long Island" Herring, C. innttitirncca. The latter name 

 was adopted by Storer for the species, but more recent authorities, guided by a rather question- 

 aide interpretation of the rules of priority, have substituted the name C. wr<//ocm, because it was 

 printed on the page preceding the other. Mitchill stated that the "Long Island" Herring occu- 

 pied a middle station between the Shad and the "Stateu Island" Herring, but it seems strange 

 that so accomplished an ichthyologist should not have at once perceived the identity of the two. 

 The name "mediocris" was founded upon small specimens. The names given this species are as- 



