OF FKUti« UF Tilt: GENUS MEGALOPHRYS. 307 



foramen, is of much greater diameter tliau the liyoglossal muscle 

 which passes through it. The inconvenience which might thus 

 result is obviated by the existence posteriorly of a tough trans- 

 lucent membrane, which largely occupies the hinder part of the 

 sinus by stretching across it. It has a clean semicirculai- edge in 

 front over which the muscle plays. I have been unable to find 

 any antei'ior cornua of the hyoid, which appears to be absent, 

 at any ra,te as a discrete cartilage, in this group of Frogs. But 

 the lateial foramina ai'e piesent and correspond, as I imagine, to 

 similar foramina in Felodi/tes 2y>('')iciatus, the development of which 

 has been worked out by Ridewood *, In Megalophrys fece they 

 transmit in the same way the glossopharyngeal nerves, than which 

 they are only just larger. The strongly ossified thyi'oiiyals have 

 the usual elongated hourglass shape. The distal cartilaginous 

 epiphysis of each of these bones has very much the shape and 

 direction that it has in Xeiiophrys monticola, to my figure of 

 wdiich I refer below t. 



The musculature of the hyoid does not appear to me to present 

 any particular features of interest as compared with allied forms. 

 The hyoglossus did not show the twisted rope-like strands that I 

 have observed and described in allied forms. Each muscle arose 

 solely from the inner and lower border of the thyrohyal bone, and 

 not at all from the flat surface of that bone. 



§ Alimentary Canal. 



The accompanying drawing (text-f]g. 127, p. 398) of the ali- 

 mentary canal of Megalo2jhrys fece may be compared with that of 

 Breviceps upon a later page (p. 407). The stomach of the Mega- 

 lophrys is longitudinally ridged by thick ridges, of which there 

 are eight in the middle of that organ. Of these only three survive 

 until the opening of the stomach into the duodenum ; the others 

 die away and cease to be ridges. The intestinal tract measures 

 104 mm., and is to be divided into a very short duodenum, a 

 wider ensuing region, and then a narrower ileum which opens 

 into the large intestine. The regions are, in fact, quite as in 

 Brevicejys. The length of the three difi:erent regions of the small 

 intestine are 6, 42, and 57 mm. respectively. Although it will be 

 observed that these measurements do not tally exactly with the 

 total length of the small intestine, it will be noted that they are 

 only divergent by 1 mm. As the measurements of the difierent 

 regions of this gut were made quite independently and without 

 any concurrent reference to the total length of the small intestine, 

 I leave them at the figures which I have given. It will be observed 

 that these proportions are very difierent from those exhibited by 

 Breviceps. There are also certain difi'erences in the ridges wdiich 



* " On the Structure and Development of tlie Hj-pobrancliial Skeleton of the 

 Pursle}' Frog {Pelochjtes punctatus),'[ P. Z. S. Ib07, p. 577. 

 t P. Z. S. 1907, p. e98, test-fig. 238. 



