232 BULLETIN OF THE 



or lowlands, north or south. The question of inaction may prove a con- 

 siderable factor in determining the profits. Other things being equal, 

 those whose wanderings are shortest are most to be depended on, since 

 their movements are less likely to change direction, or, being changed, 

 are more easily followed. Something of the nature of a marine signal 

 service will be necessary in order to follow the more erratic. It is often 

 the variation in direction and extent of their journeys that causes the 

 apparent scarcity of different kinds in particular localities, during certain 

 seasons, rather than decrease in numbers. The motions of the sharks 

 which wander most are to a greater or less degree determined by those 

 of the fishes upon which they feed. 



Caxcharias (Prionodon) obtusus. 



Sqimlus obtusus, Poey, 1858. Mem. Cub., II. 337. 

 Squalus platyodon, Poey, 1858, 1. c. 331. 



Through the exertions of Lieut. S. M. Ackley and the boatswain, Peter- 

 son, we were able to examine a number of large specimens. Several adult 

 females bore young nearly ready for delivery. When in the water the tips of the 

 fins of the large ones appeared white ; on deck the color was much more dull. 

 The fins of the young were also lighter toward the extremities, but each was 

 marked with a small black spot on the very end. The lobes of the pectorals 

 and dorsals were broadly rounded at the tips. The pectoral did not quite 

 reach to the hinder extremity of the base of the dorsal. From the base of the 

 first dorsal to the hinder end of that of the second, the distance was just twice 

 the length of the former. 



Each female had nine young ones. This was during the last week in 

 January, and probably two or three weeks before parturition, which would 

 place the time of the appearance of the young in February. The little ones 

 were about sixteen inches and a half in length, perfectly formed, and it does 

 not seem possible that their birth was anticipated more than a week or two. 

 When the cord was cut they were quite snappish, and swam away as if able to 

 take care of themselves. In one case several dead ones, far advanced in de- 

 composition, were found in the oviducts among the living, which did not appear 

 to have suffered from their presence. 



One to several specimens of an Echeneis, which I take to be E. remora, were 

 taken with each large shark. 



Cuba ; Santa Cruz ; Guadaloupe ; Dominica. 



Zygaena tiburo, Val. 



Numbers of hammerheads of this species were found among the fishes killed 

 by " the epidemic," and strewn along the shores of Florida Keys. 



