42 [February, 



very probably of rare occurrence on the coast of the Atlantic in this latitude, 

 much more so than the preceding. The four specimens alluded to, which are a 

 pair of adults and a pair of young, are now in the collection of the Philadelphia 

 Academy. 



The third species, confounded by authors with the preceding, is : 



t. Anser cceetjlescens (Linn.) 



Anas coerulescens, Linn. Syst. Nat. i. p. 198, (1766.) 



Edwards, Birds, iii. pi. 152. Wilson, Am. Orn. viii. pi. 69, fig. 5. Aud. B. of 

 Am. pi. 381, fig. 2, oct. ed. \i. pi. 381, fig. 2. 



This bird is figured and described by both Wilson and Audubon, as the young 

 of Anser hyperboreus, but neither of them appear to me to have done so on any 

 sufiBcient information, as may, I think, readily be inferred from their articles on 

 that species. That it is not the young of either of the preceding species is my 

 conclusion, being, as I believe, acquainted with the young of both. 



The figure given by Edwards as above, represents, apparently, the young of 

 this species, and those of Wilson and Audubon a more mature stage of plumage, 

 if not adult. This bird was known to the earlier naturalists, having been named 

 by Linnaeus as above, in 1766, and before him by Brisson in 1760. Both, how- 

 ever, probably described on the faith of Edwards' figure, which was published 

 in 1748. Pennant apparently does not, but gives a sufficient description of this 

 species under the name of "Blue winged Goose" in Arctic Zoology, ii, p. 269, 

 (1792.) 



If this bird is the 3"0ung of Anser hyporborens, which I deem very improbable, 

 its specific name as above is the proper designation of the species, having 

 priority over Pallas' Anser hyperboreus, or Forster's Anas nivalis (Phil. Trans. 

 London, Ixii. p. 413, 1772,) which are synonymes. It is of rare occurrence on 

 the coast of the Atlantic, in the latitude of New Jersey, though stated to be 

 abundant in the Arctic regions. Specimens in the Museum of the Philadelphia 

 Academy. 



A Synopsis of Entozoa and some of their Ecto-congeners observed by the Author. 



By Joseph Leidy, M.D. 



PROTHELMINTHA. 



1. BoDO RANARTTM Ehrcnberg. 



Abundant in the intestines of different species of frogs and toads. 



2. BoDO HELicis Diesing. 



Cryjytobia hdicis Leidy, Proc. Acad. Nat. Sci., iii, 101. 

 Cryptoicus helicis Leidy, Journ. Acad. Nat. Sci., 2d ser., i, 67. 

 Bodo helicis Diesing. Leidy, Pr. A. N. S., v, 284. 



3. BoDO coLUBRORUM Hammcrsclimidt. 

 In the cloaca of Tropidonotus sirlalis. 



4. BoDO JULiDis Leidy. 



Pr. A. N. S., V, 100; Trans. Am. Phil. Soc, 2d ser., x, 244. 



5. BoDO MUSCARUM Leidy. 



Frequent in the intestine of the house fly, 3Iusca domestica, in immense 

 quantity. 



6. Bodo melolonth.k Leidy. Body spherical; diameter .00449 to .0112 mm. 

 Tail simple, about the length of the diameter of the body. 



Found in the intestine of Melolontha quercina and 31. brunnea. 



7. BuRSAUiA iNTESTiNALis Ehrcnlj. 

 In the intestine of liana pipiens. 



8. Leucophrts stryatis Dujardin. 



Leucopkrys. Leidy, Journ. A. N. S., 2d ser., ii, 49. 

 In the liquids of the body of Enchytraeus. 



