780 DESCRIPTIO>f OF APHANTOPttRYNE, 



The division into pars stemalis and pars epicoracoidalis of the 

 pectoralis is very obscure in A. pansa. Along the line of origin 

 on the symphysis, there is no trace whatever of any differentia- 

 tion of the fiVjres; but, distally, as they approach their insertion 

 beneath the detoid and pars abdominalis, a slight separation 

 into a small anterior and a larger posterior moiety is noticeable. 

 The anterior portion, representing the pars epico7-acoida/is (Plate 

 Iv., fig. 2, pe.) of other frogs, Hnds attachment on the anterior 

 portion of the epicoracoid cartilage and the median expansion of 

 the ligament (Plate liv,, fig.lg, lig.) which lies in the position of 

 an omosternum. The posterior moiety, or the pais stem alis [Plate 

 Iv., fig. 2, /^s;:).) arises wholly from the epicoracoid and its weak 

 posterior extension. It will be evident that these fibres, desig- 

 nated as the pars sternalis, in all probability represent the portio 

 anterior of that muscle, as found in other frogs. 



This seems to exclude whatever room for doubt there exists as 

 to whether the sternal plate will be found in Aphantdphryne as 

 a separate element. In those frogs which possess a distinct 

 sternum, we find the pars sternalis invariably attaching to it. 

 If the sternum is cartilaginous, as in L. dorsalis, then the 

 muscular attachment is of a lesser extent than in the case of 

 such frogs as Ratia and Megalophrys, in which the sternum has 

 a strong, calcified style. In Aphantophryne, however, we find 

 the most posterior fibres of the pectoralis sternalis attaching to 

 the weak, posterior extension of the epicoracoid cartilage, making 

 the necessity of provision for further attachment, in the foim of 

 a sternal plate, seem quite superfluous. 



In L, dorsalis, in which there is a complete pectoral girdle, 

 with omosternum and sternal plate, and much more powerful 

 limbs, the arrangement is naturally very different. It shows 

 three distinct divisions lying one in front of the other. The 

 anterior or pars epicoracoidalis (Plate Iv., fig.3, joe.) is very like 

 that of Rana esculenta* Its fibres do not attach to the omo- 

 sternum. The median portion represents the portio aiitei-ior of 



* Hoffmann, Bronn's Klass. Thier-Reichs, Band iv., 1873-78, p. 134, Taf. 

 xvii., pe. 



