57 



very few of the descriptions of the latter animals that I have at my 

 disposal, that give the details needed for this comparison, has convinced 

 me that this conclusion is correct. 



In Salamandra maculosa, Druner (1901) describes a space called 

 by him the antrum petrosum laterale, which is said to lie between 

 the Os petroso-occipitale and the quadrate cartilage. The quadrate 

 cartilage is said to be always attached to the Os petroso-occipitale by 

 three processes, a fourth process sometimes connecting it with the 

 operculum or "dessen knorpeligen Limbus." The three constant pro- 

 cesses are all that it is necessary to here consider, and they are said 

 to belong partly to the Os petroso-occipitale and partly to the quadrate. 

 Two of them are called by Druner the processus lateralis dorsalis and 

 processus lateralis ventralis, the third one being simply referred to as 

 a cartilaginous septum (Spange) which separated the foramen trigemi- 

 num into dorsal and ventral halves. The processus lateralis dorsalis 

 is said (1. c. p. 539) to be attached to the quadrate cartilage by con- 

 nective tissue, while between the processus lateralis ventralis and the 

 quadrate cartilage there is. in the adult salamander, an articular joint. 

 It will be well to call these processes at once, as in Ceratodus (Alus, 

 1914 b), the processus oticus and processus basalis, respectively, the 

 third process being the processus ascendens. The three openings that 

 lead from the chamber to the exterior can be called the profundus, 

 trigeminus and facialis openings because of the nerves that they transmit. 



In Fig. 41, PI. 30 of his work, Druner shows this antrum ex- 

 posed, its lateral wall having been removed. In this figure it is 

 seen that the vena petroso-lateralis of Drüner's descriptions enters 

 the chamber by its profundus opening and leaves it by its facialis 

 opening, exactly as the jugular vein enters and leaves the trigemino- 

 facialis chamber in Amia and teleosts (Allis, 1897 and 1909). A branch 

 of the internal carotid artery, the arteria petrosa lateralis of Drüner's 

 descriptions, enters the chamber by its facialis opening and leaves it 

 by its trigeminus opening, exactly as the external carotid artery enters 

 and leaves the trigemino-faciaUs chamber in Scomber and the Loricati, 

 and as it would enter and leave that chamber in Amia and Lepidosteus 

 if its foramen of entrance were to fuse with the facialis opening of 

 the chamber. This artery in Salamandra is accompanied by sym- 

 pathetic nerve fibers, which fibers thus correspond to the sympathetic 

 nerve that traverses the chamber in teleosts (Allis, 1903), The tri- 

 geminus and profundus nerves enter the chamber, in Salamandra, 



