No. 11. — Reports on the Results of Dredging, under the Supervision 
of ALEXANDER AGASSIZ, along the Atlantic Coast of the United 
States, during the Summer of 1880, by the U. S. Coast Survey 
Steamer “ Blake,” COMMANDER J. R. BARTLETT, U. S. N., Com- 
manding. 
(Published by permission of CARLILE P. PATTERSON, Supt. U. S. Coast and 
Geodetic Survey.) 
XII. 
Report on the Selachians, by SAMUEL GARMAN. 
Tus notice includes only what were taken during the last cruise of 
the steamer, with a few shoal-water species previously obtained. No 
attempt having been made to secure the latter, the collection is small. 
A single new species and a new variety were found among the captures 
in depths of less than thirty fathoms. All those coming from great 
depths appear to belong to species heretofore unknown. The notes 
secured on the different expeditions, as far as they relate to the Sela- 
chians, are by themselves insufficient for purposes of generalization. 
In connection with those taken from the results of other work, on 
Fishes as well as Selachia, they seem to point toward the following 
conclusions : — 
First, That the migrations of these animals, including the fishes, are 
much more limited in extent than has generally been supposed ; and, 
Second, That these creatures are more or less affected by a period of 
comparative inaction, in a measure corresponding to what obtains among 
Batrachia and Reptilia, most pronounced, perhaps, in the case of such 
as the skates. 
Among both Selachians and Fishes there are many species in our waters 
whose movements do not amount to more than short runs from shoal to 
deeper water and back again. ‘Others would seem to extend their travels 
from the coasts and banks to the Gulf Stream. And still others make 
much more extensive migrations. It is only a question of time and 
further investigation to enable our fishermen to follow their game with 
nearly as much certainty as the hunter now follows his, from highlands 
VOL. VIII. — NO. 11. 
