112 BULLETIN OF THE ESSEX INSTITUTE. 



trabecula. The short so-called ' palatine cartilage ' is, 

 as has been shown by Gaupp, the homologue of the ant- 

 orbital process of the Urodela. 



The quadrate is situated much nearer the posterior end 

 of the skull than that of the Urodela described. It lies 

 about under the middle of the lateral wall of the otic cap- 

 sule, to which it is connected by means of a dorsal otic 

 and a ventral palato-basal process. There is no stapedial 

 process connecting the quadrate directly with the stapes, 

 but, as was mentioned above, the stapes is connected with 

 the tympanic annulus which is earlier derived from the 

 quadrate. A slender palato-pterygoid process {ppt) 

 projects forward from the body of the quadrate and fuses 

 with the lateral margin of the lamina cribrosa. The rela- 

 tively posterior position of the quadrate adds proportion- 

 ately to the length of Meckel's cartilage. 



Anura and Urodela contrasted. 



From a general view of the chondrocrania of these two 

 groups it is seen that, on the whole, in the Anura the width 

 is greater in proportion to its length than in the Urodela. 

 But since there are many very short and broad skulls 

 among the Urodela this distinction is of little value. The 

 closure of the cranial cavity is more complete in the An- 

 ura, especially in the ventral region whore the basicranial 

 fontanelle, as shown by Gaupp ('93), becomes greatly re- 

 duced. Here, too, instead of ending freely, the pterygoid 

 process of the quadrate is attached anteriorly to the eth- 

 moid plate. In these two last mentioned points the Anura 

 show more resemblance to the Selachians than do the 

 Urodela. 



We may here insert a few words in regard to the ho- 

 mologies and terminology of the cartilages which have 



