868 DR. C. F. SONNTAG ON THE VISCERAL ANATOMY 



The dorsal surface of the bladder of Denclrolagus ursinus is 

 connected to the dorsal abdominal wall at the sides of the 

 vertebral column by two strong ligaments, which divide the pelvic 

 cavity into a median and two lateral compartments. The central 

 one contains the rectum and uterus, and the oviducts curl over 

 the fi'ee edges of the ligaments. 



In Perameles obesula the uterus is separated from the rectum 

 by the wall of the peritoneal pocket formed by the fusion of the 

 splenic and duodenal ligaments. 



I have nothing to add to the existing descriptions of the 

 generative organs of either sex, nor to Osgood's resume of our 

 knowledge of the marsupial bones (9). In the latter paper the 

 nipples are also enumerated, and it is shown that they are 

 asymmetrically arranged in the Didelphyidfe alone. 



■ The Ductless Glands. 

 The sup7Ycre)ial capsules are situated on the mesial aspects of 

 the antei'ior poles of the kidneys in all Marsupials examined by 

 me except Phascolarctos cinei-eus, and that species has a very 

 prominent ligament uniting the left kidney and its capsule. 



The Thymus Gland. 



The Polyprotodonts difler from the Diprotodonts in the charac- 

 ters of the thymus gland. In the former it consists of two 

 elongated or oval bodies in the anterior part of the thorax, but 

 in the latter there are two cervical lobes in addition ; and one 

 must be careful to distinguish them from salivary glands. 

 Osgood (9) found four thoracic glands in Cctnolesfes. 



Topography : — The cervical lobes lie immediately under cover 

 of the platysma. They are oval or pyriform, with the narrow 

 ends turned forwards. They lie at the root of the neck, as in 

 Bendrolagus m^sinus (text-fig. 74 B), Macropus giganteus 

 (text-fig. 71, k), and Macropus rufiis, or they may extend far 

 forwards and even conceal one of the submaxillary glands, as in 

 Petaurus sciureits (text-fig. 73, k). They may touch the parotid 

 glands anteriorly, or be in contact with them throughout the 

 entire length of the neck as in Trichosurus vidpecida. In Pseudo- 

 chir us peregrin-US they are concealed by the parotid glands. They 

 may be in contact with the mid line, or an interval in which the 

 pretracheal muscles are seen may sepai-ate them. The subjacent 

 structures are the sterno-mastoids, pretracheal muscles, and part 

 of the sternum a,nd clavicles. 



The surfaces may be finely or coarsely lobulated, and in no case 

 were they invested by a connective- tissue capsule derived from 

 the cervical fascia. 



Symington (17) described and figured the topography of the 

 thoracic lobes, and described the gland in a number of Marsupials. 

 His observations on the Polyprotodonts are limited to Didelphys 

 virginiana and Basyxiruscancrivora. He could not detect cervical 



