458 PROCEEDINGS OF THE ACADEMY OF 



Circulatory Apparatus As my smallest specimen was very well 

 injected by Mr. Nash, the preparateur of the University Museum, 

 I took interest in comparing the great bloodvessels and various 

 rete mirabile with those described and handsomely figured by Dr. 

 Murie, and found his account a very satisfactory one I must 

 state, however, that the rete mirabile, figured by Dr. Murie in 

 Plate 24, Fig. 30, as lying immediately underneath and alongside 

 of the trachea and upper portion of the bronchi, was absent in my 

 specimen. I cannot attribute this difference to want of the vessels 

 being filled in my specimen, as the other rete, such as the cervical, 

 cranial, spinal, axillaiy, brachial, thoracic, intercostal, caudal, 

 etc., were well injected, so that without questioning the correct- 

 ness of Dr. Murie's plate as illustrating his dissection, I simply 

 state that in this respect it does not give exactly the idea of mine. 

 As Dr. Murie gives measurements of the bifid heart when empty, 

 I offer the following as the size of that organ when distended with 

 the injected material: Width of heart through auricles, measured 

 across aorta and pulmonary artery, 7 inches ; the width of aorta 

 was a little over an inch, that of pulmonary artery 1^ inch ; width 

 of heart through ventricles G^ inches. It is interesting to notice 

 the presence of the two superior venas cavae, the right one opening 

 into the auricle above, the left one below. 



Uro-genital Apparatus. Among the striking differences that 

 the Sirenia offer as contrasted with the Cetacea, none deserve 

 more notice than the urinary and Generative organs. As is well 

 known, the kidney in the Cetacea is much lobulated, whereas in 

 the Manatee no trace of such lobulation is perceptible. The kid- 

 neys in the smallest Manatee dissected by me were 6 inches long 

 and 3 inches wide; the ureters of the same diameter throughout 

 measured 10 inches in length from bladder to pelvis. As the male 

 generative organs have been described, and partly figured by 

 Vrolik, I merely mention that the penis in my specimen measured 

 12 inches in length, and that the ischio cavernosus, bulbo urethras, 

 :ind retractor penis muscles were well developed. The seminal 

 vesicles which are absent in the Cetacea were 2 inches long in my 

 specimen. The vas deferens from point of union with duct of 

 seminal vesicle to epididymis measured 8 inches; the testicle, 3 

 inches long, was somewhat indented, giving the gland the appear- 

 ance of consisting of two or three bodies. 



Habits of the Manatee. A great disideratum for a long time in 



