A winter migrant, arriving in small flocks about the 20th September. 157. FREGATA MINOR. *. Fairly common, frequenting the coast during rough weather. VI. On the Alimentary Canal of the Martineta Tinamou (Calodromas elegans) *. By FRANK E. BEDDARD, M.A., Prosector to the Zoological Society of London, Lecturer on Biology at Guy's Hospital. MR. W. H. HUDSON, in a paper upon the habits of certain South-American birds†, makes the following observations upon a remarkable point in the anatomy of the Martineta Tinamou :-"The structure of the intestinal canal in the Martineta [i. e. Calodromas elegans] is most extraordinary, and totally unlike that of any other bird I have ever dissected; the canal divides near the stomach into a pair of great ducts that extend almost the entire length of the abdominal cavity, and are thickly set with rows of large membranous clam-shaped protuberances." This passage, as well as a general account of the bird, is repeated in the recently published Argentine Ornithology' of Messrs. Sclater and Hudson, where, however, the wording has been slightly altered, as in the latter work "claw"-shaped is written instead of clam-shaped. It is perfectly evident from the quotation that Mr. Hudson had noticed some remarkable divergence from the normal structure of birds in dissecting the "Martineta," but it would be difficult to surmise what this peculiarity is from reading This paper was communicated to the Meeting of the British Association at Newcastle in September last. "On the Birds of the Rio Negro of Patagonia," P. Z. S. 1872, p. 546. See also Sclater and Hudson, Argent. Orn. ii. p. 214. Mr. Hudson's remarks. I am, however, through the kindness of Mr. Sclater, able to set this question at rest. Mr. Sclater received a number of specimens of this Tinamou from Cæca of Nothura maculosa, distended with alcohol, nat. size. Mr. D. A. Shennan, F.Z.S., of Negretti, Villa Nueva, Buenos Ayres, whose attention he had specially drawn to this curious point in its structure. These specimens, carefully preserved and packed in several large glass bottles placed in a case, were, with great liberality, handed over to me by Mr. Sclater for study and description. On opening the first individual, I saw directly that Mr. Hudson had not in any way exaggerated the remarkable appearance presented by a part of the alimentary canal; but that instead of being diverticula of the stomach, as might possibly be inferred from Mr. Hudson's description, the two tubes in question are simply the cæca, which, in this bird, as in so many others, lie across the abdominal cavity and reach as far as the gizzard. So far, then, there is nothing abnormal about the anatomy of Calodromas elegans; it would be abnormal, in fact, if it did not possess cæca: these appendages of the alimentary tract are invariably (so far as our present knowledge goes) found in the Crypturi; they are proportionately of large size, and like those of Gallinaceous birds in being rather thin. This will be seen by the figure of the cæca of Nothura maculosa (fig. 1, p. 62), taken from those of a fresh specimen which have been distended by alcohol. It was an extremely difficult task to distend the cæca of Calodromas; they were tolerably full of semidigested food, among which was a great quantity of minute sharp-edged pebbles; these were forced against the walls of the cæca by the pressure of the water employed to clean out the alimentary tract, and easily cut their way through. In no case was it found possible to make a good permanent preparation of the cæca; but in one instance the cæca remained distended for a sufficiently long time to enable Mr. Smit to make the accurate drawing which is reproduced in the accompanying woodcut (fig. 2, p. 64). From that drawing it will be at once seen that the cæca of Calodromas elegans not only differ from those of all other Crypturi, but that their form is quite unique among birds. Instead of being simple tubes, the cæca of Calodromas are furnished with numerous minute diverticula, which are crowded together and are particularly well developed in the lower part of the cæca. Towards the free extremities the |