202 BOTTLENOSE PORPOISE — TRUE. 



young iu their efforts to breathe by bearing them up to the surface of 

 the water ou their flippers, or otherwise. I did uot observe this action 

 myself. 



The spiracle, or blow-hole, appears to be a sensitive part of the head. 

 When I touched it with my hand the porpoises invariably showed 

 signs of discomfort by lashing the tail violently. 



The eyelids appeared to be as mobile as in the ordinary terrestrial 



mammalia. They were closed when the hand was brought near the 



eye. The iris of the eye is brown. The contraction 



Oand expansion of the pupil take place in a peculiar and 

 remarkable manner, as shown in figure 1. When con- 

 tracted the pupil takes the form of a semicircular line 

 with the convexity* downward. When expanded the 

 aperture is wide, and has nearly the form of a half- 

 ellipse. To produce these different effects, the lateral 

 and lower parts of the iris remain nearly or quite 

 Fig. i.-a, Pupil con- Stationary, while the superior portion is either drawn 

 tracted; b, Pupil di- upward Or allowcd to drop downward. 

 '**®'^' These porpoises appear to be subject to disease and 



to encounter various accidents. Colonel Wainwright informed me that 

 one porpoise taken at the fishery had a piece of cable lying across the 

 mouth near the last tooth. There were evidences that it had originally 

 been of considerable length and h^d trailed along the sides. In certain 

 individuals some shot was found, and in one a portion of the sword of a 

 sword-fish. 



Among the porpoises which I examined, one had a deformed dorsal 

 fin, and in another the end of the pectoral fin was twisted out of its 

 natural plane and much thickened. All the porpoises were marked 

 with fresh scratches and the scars of earlier ones. The males bore 

 more of these marks than the females. One female had a diseased jaw ; 

 the skin of this part was tumid and bark-like, and of a white color. 

 Many individuals have, besides scratches, certain smooth, circular, white 

 blotches on the skin, which are apparently due to disease of parasitic 

 origin. 



Certain of the porpoises which appear in the spring are called " tas- 

 sel-fins" by the fishermen. I discovered that these were individuals 

 which bore on their fins a greater or less number of parasitic cirriped 

 crustaceans of the genus Xenobalanus. The specimens which I col- 

 lected are not now at hand, and I can not therefore state positively to 

 what species they belonged. They appeared, however, to be Xenobal- 

 anus globicipitis of Steenstrup. Three or four of the porpoises taken 

 May 19 were accompanied by these i^arasites. The fishermen informed 

 me that the parasites were first seen in May or at the end of April, but 

 did not know whether they could be found on the porpoises in summer. 

 None are seen, however, when the fishing is resumed in the autumn. 



