1908.] ANATOMY OF A FROG. 29 



complete bar uninterruptecl in the dorsal middle line. None of 

 the fibres of the muscle appear to me to actually run on to the 

 cricoid bar ; but their action must result in moving this bar, seeing 

 that it is intimately and strongly connected by their walls with 

 the lungs. Any pull on the roots of the two lungs must tend to 

 raise the cricoid cartilage dorsally. 



§ Abdominal Viscera. 



The Liver of this Frog (text-fig. 8) is of large size and has the 

 unusual character among the Batrachia Salientia that the right lobe 

 is considerably the larger of the two lobes into which it is divided. 

 Furthermore, the left lobe can hai'dly be said to be divided into 

 two lobes, as is again so frequently the case with Frogs, though an 

 indentation on its border is an indication of such a subdivision. 

 The liver is, as a whole, very squai'e-shaped. Anteriorl}'- its 

 boundary line is almost straight and is on a level with the 

 posterior border of the coracoid. The two lobes are nearly in 

 contact in the middle line and hardly diverge posteriorly, so that 

 the posterior border of the liver is almost straight. Anteriorly, 

 however, in the middle line they diverge slightly and form a small 

 triangular space ; this discovers the heart, which is otherwise 

 quite covered by the liver except for the narrow median ventral 

 slit between the two liver-lobes, where it is apparent. The apex 

 of the ventricle is situated a little way in front of the posterior 

 border of the liver. The smaller left lobe is more triangular in 

 shape than the right lobe. The gall-bladder is quite invisible on 

 a superficial view ; it lies beneath the inner corner of the right 

 lobe. As far as I can gather from Dr. Giintlier's account of the 

 Bufonid Rhinophrynus dorsalis*, the liver of this toad bears 

 some likeness to that of Breviceps. For he remarks f that the 

 heart of Rldnophrynus " is surrounded by the liver in a similar 

 way as in higher animals, as in other Batrachians it is suri-ounded 

 by the lungs." Furthermore, he observes of the liver that it is 

 divided into a right half and a larger left half. This would seem 

 to be the exact converse of what I note here in Breviceps. But 

 elsewhere in the paper Dr. GUnther speaks of the stomach being- 

 situated " quite on the right hand," which causes me to doubt 

 whether right and left may not be used to express the positions as 

 seen from above during a dissection. Furthermore the liver 

 extends dorsally to the heart, which thus lies in cavities as it 

 were excavated in the liver-substance, and it is almost completely 

 surrounded and hidden by that viscus as in Reptiles and Birds. 

 The likeness between Rhinophrynus and Breviceps in these features, 

 of liver construction are remarkable as possibly related to the ant- 

 eating habit which they have in common, since systematically 

 they are placed in difierent families. Part of the stomach is con- 

 cealed by the left lobe of the liver, and the small intestine passes 



* " The Systematic Arrangement of the Tailless Batrachians, &c.," P. Z. S. 1858 

 p. 339. t Ijoc. cit. p. 350. '" 



