164 DR. R. J. ANDERSON ON THE [Mar. 16, 



Pelvic girdle. Shoulder-girdle. 



1. Pubis. 1. Procoracoid. 



2. Ischium. 2. Coracoid. 



3. Ilium. 3. Scapula. 



4. Subilium. 4. Subscapula. 



5. Wanting. 5. Olaviele. 



6. Wanting. 6. Interclavicle. 



7. Pelvisternum. 7. Omosternum. 



(Ischio-pubic symphysial carti- Coraco-procoracoid symphysial 



lage. Osseous pelvisternum of cartilage. 

 Edentates.) 



8. Hemi-pelvisternum. 8. Hemi-omosternum. 



9. Ischio-pubic symphysis. 9. Symphysis coraco-procoracoid. 



10. Prepelvisternum. 10. Preomosternum. 



Preomostema of Anoura. 



11. Hemi-pelvisterna. 11. Hemi-preomosterna. 



Epipelvic ossicles of Ohame- Substernal bones of mammals, 

 leons. 



Marsupial bones of Monotreiues 

 and Marsupials. 



12. Post-pel visternum. 12. Post-omosternum. 



Os cloacae of Lacertilians. 



The pelvis of Lacerta muralis is figured by Prof. Hoffmann in 

 Brcnn's 'Thierreichs,' and Briihl also gives figures of the Amphibian 

 forms. In a specimen of Iguana tuberculata in this museum 

 the pubis is a separate bone, and contains a preacetabular foramen 

 as well as a well-marked supra- or prepubic notch. A copula (bone) 

 reaches from the anterior part of the ischium to the pubis, wider 

 behind than in front. The os cloacae fits into the ischial symphysis 

 behind, and the ischial symphysis still shows the marks of union with 

 the tuberosities. The ilia articulate each with two transverse pro- 

 cesses, and the traces of union with the ischium are obliterated. 



In the Australian Monitor gouldii which we have, a prepubic 

 nodule fits in between the pubes in front ; all traces of union between 

 the parts of the ossa innominata are obliterated. A small nodule is 

 situated in front of the ischial symphysis, and a distinct os cloacae is 

 present behind, and, as in the Iguana, fits in between the ischia. A 

 prominent ischial spine l)ehind is situated at the junction of the 

 middle and outer third of the posterior border of that bone. In 

 Lacerta viridis a prepubic nodule and a postischial are present. In 

 the West-Australian Moloch horridus (marked 1845 in the catalogue) 

 the postischial bone is quite evident, and a large copula runs forwards 

 to the pelvis. In our Chameleon the three pelvic bones are short, 

 and the os cloacae seems to be cartilaginous ; the ischio-pubic copula 

 is reduced to a thread-like structure. The os cloacaa and prepubic 

 bone are thin in our specimen of Ameiva, but they are very distinct. 



Prof. Owen, in his ' Anatomy,' says that in the Potoroo there is 

 a triangular ossicle developed at an early period, which is wedged 

 into the posterior interspace of the ischio-pubic symphysis ; and in 

 his paper in this Society's 'Transactions' he figures the posterior 

 epiphysial bone. In the skeleton of a Kangaroo in our museum 

 the following measurements were made : — 



