OCCURRENCE OF ECHINOSTOMUM SPINULOSUM 
RUD. 
N. C. GILBERT. 
IN THE intestinal coeca of an adult male Loon (Gavia imber) 
killed near Ann Arbor, Michigan, in April, 1904, I found from 
forty to fifty mature distomes, which I have identified as Echin- 
ostomum spinulosum Rudolphi, a worm which I have not been 
able to find hitherto reported for North America. Later, in 
August of the same year, I obtained eight more specimens from 
the intestine of a Bonaparte's Gull (Zarus philadelphia). In 
each case the specimens were in a badly macerated condition. 
There was this unimportant difference from the European 
species, that my specimens averaged somewhat smaller. Their 
length was about 2.37 mm., while the length for the European 
species is given as from 3-10 mm. (Stossich, '92). The ana- 
tomical differences are also very slight between this species and 
E. pseudoechinatum Olsson, Æ. euryporum Loos, E. mordax 
Loos, and Æ. pendulum Loos, and make this species very dif- 
ficult to differentiate. These differences are, however, very 
accurately described by Loos ('99), and although slight, seem 
constant. 
The body of the specimens which I obtained is elongated, 
subcylindrical, widest at the acetabulum, and tapers gradually 
posteriorly. Length, 2.37 mm.; width at acetabulum, 0.29 mm. 
The neck is constricted, and is armed with spines, arranged in 
regular rows, which extend as far as the posterior border of the 
acetabulum. The anterior end is conical in shape, with an 
expanded base, and is armed with twenty-two oral spines, in a 
single row, and of equal size. + 
The oral sucker is located at the extreme anterior end ; diam- 
eter, 0.08 mm. The acetabulum is located 0.61 mm. from tHe 
anterior end ; diameter 0.17 mm. The pharynx is located close 
behind the oral sucker, and the intestine divides just anterior to 
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