THK liKDoKI.YN IXSTITUTE OF ARTS AND SCIKNCKS 
BROOKLYN MUSEUM 
SCIENCE BUIvLETIN 
VOL. 3, NO. I 
LONG ISLAND FAUNAE IV. 
THE SHARKS (Order SELACHH ) 
By John Tre.vdwell Nichols and Robert Cushman Murphy 
Sharklike forms, not unlike those of to-da\-, were among the ver\- 
earlie-st of fishes to be found on the earth. It is therefore natural to find 
the structure of the sharks simjile and primitive as comjiared with that of 
other fishes. On the other hand, their mode of reproduction is highly 
specialized. The eggs of .some kinds are hatched within the body cavit>- 
of the mother, and the young, born full}' develo])ed, are often quite 
sizable individuals ; witli others the eggs are few and large, laid .singl\- 
and enclosed in a peculiarly formed capsule. 
The sharklike fishes maN' be .separated into two groups : i , more or 
le.ss cylindrical or compres.sed forms — the true sharks ; and 2, broad, flat, 
depressed .species, man\- of them s]:)ecialized for l\"ing on the bottom — the 
rays. In this pai)er the former alone are dealt with, and only such s])ecies 
as occur in water of twent3'-five fathoms' de])th or less. There is, 
however, an almost perfect series of connecting links between the sharks 
and the ra^-s, and we have included one of them, Sqnafiita, in the i^re.sent 
discussion. This very i^eculiar fi.sh might with equal propriety be ]>laced 
in the other grouj^ but that it has the gill-openings more or le.ss lateral 
in.stead of .strictly on the lower surface, as in the rays. 
The sharks are generall\- large fishes with a curved, transver.se 
mouth on the under side of the head, and an assnimetrical caudal fin, 
the upper lobe of which is the longer. The>- ha\-e no ])latelike or 
overlapjnng scales, and their more or le.ss rough skin extends over the 
flipperlike fins. The latter are very difi"erent from the fins of most fi.shes, 
in which a framework of si)ines or ra>-s is connected b\- delicate 
I- Previou.s papers of thi.s .series were grouped under the heading "Long 
Island r'auna and Flora." vSince the Brooklyn Botanic (iarden has taken over the 
herbarium and botanical library, which were formerly deposited in the Museum, it is 
not likely that botanical publications will henceforth be i.ssued in the Science 
Bulletin.— Ed. 
