Page 335. 
334 ON THE ANATOMY OF PLOTUS ANHINGA.” 
therefore enters the colon by a lateral, slit-like opening. In the 
Cranes the caca are generally between 5 and 6 inches long; and they 
being so much larger, the comparative size is much the same. In 
Ibis, Platalea, and Eurypyga they are very much shorter; in Cariama 
they measure 10 inches, whilst in Psophia their.length is much the 
same as in Aramus. 
54. NOTES ON THE ANATOMY OF PLOTUS 
ANHINGA.* 
(Plates X VITI—XX.) 
Tur Darter is one of those birds whose anatomy, with the exception 
of its skeleton, is comparatively little known; I therefore take the 
present opportunity of describing the organs and some of the most 
important muscles of Plotus anhinga from the two specimens which 
were recently living in the Society’s collection, and which, from my 
prosectorial advantages, it has been my good fortune to be able to 
dissect. 
On December 28th, 1872, the Society became possessed, for the 
first time, by purchase, of a male specimen of Plotus anhinga, which 
died on the 17th of last month, with general jaundice and distention 
of the gall-bladder from obstruction of the common bile-duct. The 
second specimen, a female, was purchased on the 30th of September, 
1875; it was never quite healthy, and died on the 7th of February, 
without any special organic lesions, but with a dropsical condition of 
the subcutaneous areolar tissues, frequently found in Steganopod 
birds. It is this second specimen which I first dissected; and the 
other coming to hand, opportunely for me, has enabled me to verify _ 
my observations. 
Pterylographically, there is nothing for me to add to the results 
arrived at by Nitzsch.t ‘The skin is not in the least pneumatic, in 
which respect it contrasts greatly with Sula and Pelecanus, and agrees 
with Phalacrocoraz. ; 
With reference to the anatomy of its circulatory organs, it is to 
be noted that Plotus anhinga possesses only a single carotid artery, the 
* “Proceedings of the Zoological Society,” 1876, pp. 385-45. Pls. XXVI— 
XXVIII. Read, April 4, 1876. 
+ “Pterylography,” Ray Society’s Translation, edited by P. L. Sclater, F.RS., 
p. 151. 
