8 BROOKLYN MI'SP:1'M SCIKNCE BULLKTIN 3. I. 
Since it will take aii\ bait, 1)> uiij:;ht or da\-, the cloj^fish is frequentl> 
caught b}- fishermen who are in pursuit of other species. It is also some- 
what of a scavenger : we have found glass bottles and other rubl)ish in 
its stomach. Careful oljservation and experiment have shown ^ that it 
relies chiefl\- on its keen .sense of smell for finding food. It swims 
lazily along until it scents its pre\ , ])erhaps a crab lying out of sight in 
a tuft of waving eel-gra.ss ; then it turns, and rapidlx' moving the head 
from side to side, begins a .sy.stematic search over the bottom, circling 
closer and clo.ser to the hiding cru.stacean, which is finally seized with 
a rush, shaken as a terrier shakes a rat, and quickly swallowed. 
In common with other sharks, this species shows remarkable vitalit\- 
and recuperative ])ower after injury. A specimen taken in Buzzard's 
Bay had a large, thoroughly healed opening through the wall of its bod>-. 
Into this hole a lobe of the liver had grown, forming a free plug which 
had served efficiently to repair a wound from which ])robably no higher 
vertebrate could have recovered. ^ 
That the smooth dogfish is not more used for food in this countr\' 
seems entireh' due to prejudice. Its flesh is boneless, nutritious, and 
palatable. ^ 
3. TIGER SHARK 
Galcoccrdo tigrinns Miiller & Henle 
Jordan and Everniann, p. 32. 
Galcoccrdo airticus, Gannan, p. 14S. 
First dorsal fin decidedly larger than second dorsal, opposite space between 
pectoral and ventral fins. Teeth alike in both jaws, large, coarsely-serrate, with an 
obliqne tip and a notch below it in their outer margin. Brown, with numerous dark 
spots larger than the eye ; adult nearly plain. Length 15 to 30 feet. 
3. 1913. Parker, G. H. & Sheldon, R. E. Bull. U. vS. Bur. Fish., 191 2, p. 33. 
4- Murphy, R. C. Science, 1912, No. 905, p. 693. 
5- Field, /. c. 
