RESEARCHES IN HEI^MINTHOLOGY AND PARASITOLOGY. 1 37 



Filaria Spelcea. — Body filiform, translucent whitish, tapering at 

 the extremities. Cephalic end straight, obtusely rounded, fur- 

 nished with four equidistant papillae around the mouth. Caudal 

 end narrowest, rather abruptly attenuated and spirally rolled once 

 or twice and terminating obtusely. A di.stinct anal aperture ob- 

 servable in the female. A row of eight papillae on each side ven- 

 trally of the caudal end of the male ; three in advance and the 

 others back of the genital aperture. Penis a long, tubular style, 

 thick at the upper part, narrow and curved below. Accessory 

 piece a short, thick, curved tube, widening at the upper end in a 

 spade-like, furcate portion. CEsophagus long, cylindrical, as wide 

 as the succeeding intestine. 



Measurements. — Female, length 10 inches, thickness i-4th line. 

 Length of tail from anal aperture 7-8ths mm. Male, length 4 to 

 4^-2 inches ; thickness i-66th inch. Tail, from genital aperture, 

 forms 2-3ds of a circle % a mm. in diameter. Penis y-Sths mm. 

 long ; accessory piece i-5th mm. long. 



[April, 1875. No. 423. See Bibliography.] 



On Psorospenns in a Mallard Duck. — Prof. Leidy remarked that 

 Dr. Elliott Coues had recently submitted to his examination some 

 portions of the flesh of a mallard duck preserved in glycerine. The 

 interstices of the muscles of the duck were stated in the letter which 

 accompanied the specimens to be everywhere occupied by abundance 

 of parasites. Specimens of these in the portions of flesh examined 

 proved to be oval white bodies from one to two inches long and 

 about one-third of a line thick. Beneath the microscope they were 

 found to contain myriads of fusiform corpuscles, resembling minute 

 naviculae and measuring about the i- 1500th of an inch in length. 

 Similar bodies were first discovered in many fish by the late Prof. 

 J. Miiller and described by him as parasiies under the name of 

 Psorospenns. They have been repeatedly observed since by Ret- 

 zins, Robin, and others in the muscles and other parts of fishes, and 

 they are usually regarded as vegetable parasites. I have not pre- 

 viously heard of similar organisms having been detected in birds. 

 Though the mallard is not a fish-eater, the bird may have become 

 infected by having swallowed an infected fish. 



[September, 1875. No. 424. See Bibliography.] 



On Mermis Acuminata. — Prof. Leidy exhibited a living specimen 

 of Mermis acuminata, which had been sent to him for examination 



