PARASITES OF FISHES OF BEAUFORT, NORTH CAROLINA. 



339 



LIST OF FIFTY-NINE SPECIES OF BEAUFORT FISHES WITH NOTES ON FOOD AND 

 ON THE PARASITES FOUND IN THEM IN JULY AND AUGUST 1901 AND 1902. 



Carcharhinus obscurus, Dusky Shark. 



These sharks are referred to this species although they do not agree in all diagnostic features with 

 the descriptions published in Jordan & Gilbert's Fishes of North America, or Jordan & Evermann's 

 later work. The pectorals do not reach quite to the lirst dorsal. Tin- second dorsal is larger than 

 the anal. There is not much difference between the upper and lower teeth. They agree rather well 

 with Prionaee in the character of the fins, but the nose is much shorter and broader than in that genus. 



The specimen examined on July 26 had been caught less than an hour before by Mr. Russell J. 

 Coles. It was a much cleaner cut and more graceful shark than any other seen by me at Beaufort 

 The tips of the pectorals were black, a character not noted in the others. The specimen taken on July 

 29 -was caught at the Fish Commission wharf and was seen by me while it was still alive. Mr. Coles 

 stated that the tips of all the fins of his specimen were black when it was first captured. He also said 

 that it was much more voracious and gamy than the others he had taken. 



NEMATODES. 



1. Ascaris habena Linton. 



1902. — July 26, 1 female. This specimen was not in good condition and looked as if it had been 

 introduced recently with the food, but was not in the proper final host; length 45 turn. 



2. Ascaris brevicapitata Linton. [Figs. 22, L': 1 !.] 



1902. — Aug. 26, 8, immature. Five of these were taken directly from thestomach; the others were 

 found in washings from thestomach and intestine. One of the smaller forms was transparent enough 

 to allow it to be demonstrate) 1 that it belonged to the type which has a diverticulum of the intestine and 

 an elongated basal enlargement of t lie 1 esi ipnagus. This character in the encapsuled and immature forms 

 found in various teleosts is associated with a corrugated postanal region, which, however, was not the 

 case with these worms. They were found with their heads penetrating the mucus membrane of their 

 host, where they caused some irritation, as was evidenced by the inflamed condition of the mucus 

 membrane where they were attached. 



The shortest measured 10 mm. in length, the longest 20. Some were slender, others were plump. 

 There was considerable variation in the shape of the posterior end, but all agreed in having rather 

 thickish lips at the anal aperture. 



The jaws, while not fully developed, are seen to be those of a very short-jawed species. The 

 specimens are referred provisionally to the species .1. brevicapitata, which was originally described from 

 the tiger shark. 



CESTODES. 



3. Anthobothrium lacinialum Linton. 



1901.— July X, few. 



1902.— July '-'<>, 2. July 29, ::. Aug. li«». numerous. All found in the intestine. 



4. Orossobothrium angustum Linton. 



1901. — July 8, very numerous. 



1902. — July II, few and small. July 2H, 2. July 29, 36. Aug. 26, very numerous. All from 

 intestine. 



