82 PROCEEDINGS OF THE NATIONAL MUSEUM. vol.46. 



The females of the three species of Rictularia known from car- 

 nivores are so very much alike that it is difficult to compile a key 

 for their differentiation, which is the more unfortunate in that the 

 female, as is the rule among nematodes, is the one most likely to be 

 collected and collected in larger numbers. 



The following notations will add something of use in differentia- 

 tion: The female of R. splendida is the smallest and that of R. affinis 

 the largest, the three species making a series in which the maximum of 

 a smaller species is the minimum of the next larger, as follows: R. 

 splendida 8.37 to 10.55 mm., R. caUrensis 10.5 to 13.5 mm., R. affinis 

 13.5 to 20.5 nun. The last-named species has also a distinctly longer 

 esophagus than the others, but has smaller eggs. The egg dimen- 

 sions are as follows : R. splendida 38 to 42 /z by 32 to 34 ,«, R. caMrensis 

 39 to 42 fji by 26 to 28 fi, R. affinis 36 to 38 ix by 24 to 26 n. Jager- 

 sldold figures the first comb of both his species as closer to the base of 

 the buccal capsule than is the case in R. splendida, and I have included 

 this distinction in my key. He makes no statement in regard to 

 this point in his text and the distinction may not be found to be a 

 good one. 



As regards the males, R. splendida and R. cahirensis are about the 

 same size, while the male of R. affinis is about half as large again. 

 The last-named male also has a longer esophagus, as would be 

 expected, and wider annulations (10 to 14 fi). 



Since the parasites of the coyotes, as pointed out in my introduc- 

 tory paragraph, are of considerable economic importance, I have 

 summarized here the records of parasites from coyotes so far as they 

 are known to me. 



Protozoa. — Opalinopsis nucleololata was described as a new species 

 from the liver of Canis latrans by Smith and Fox (1908). The para- 

 site had set up pathological alterations in the liver of the coyote, 

 which was an inbred specimen from the Philadelphia Zoological 

 Gardens. 



Trematoda. — Ampliimerus pseudofelineus was recorded from the gall 

 ducts of Canis latrans at Lincobi, Nebraska, by Ward (1895) under 

 the name of Bistoma felineum. Later, Ward (1901) transferred this 

 to the genus OpisthorcMs, making it a new species, 0. pseudofelineus. 

 Subsequently Barker (1911) transferred it to his new genus, Amplii- 

 merus. 



Cestoda. — Multiceps multiceps was reported from the intestine of 

 Canis nebracensis at Washington, District of Columbia, by Hall 

 (1911), the infection being experimentally developed by feeding 

 scolices from the gid bladder worm, or coenurus, of sheep. A second 

 similar case was also reported by Hall (1912&). 



Tsenia pisiformis is here reported for the first time from the intes- 

 tine of Canis nehracensis on the basis of specimens from Montana and 



