THE NASAL ORGANS OF PIPA AMERICANA. 107 



LITERATURE. 



'94, Arnold, G. A. The anterior cranial nerves of Pipa americana. 

 Tufts College Studies, No. 1. 



'84, Blaue, J. Untersuchungen iiber den Bau der Nasenschleimhaut 

 bei Fischen und Amphibieu. Arch. Anat. u. Phys., Anat. Abth., 1884. 



'77, Born, G. tjber die Nasenhohle und den Tliranennasengang der 

 Amphibien. Morph. Jalirbuch, ii, 1870. 



'43, Fischer, J. G. Amphibiorum nudorum neurologiiB specimen 

 primum. Berlin, 1843. 



'93, Lee, Stewart. Zur Kenntniss der Olfactorius. Berichte Na- 

 turf. Gesellsch. Freiburg i. B., vii, 1873. 



'95, Seydel, O. Lber die Nasenhohle und das Jacobson'sche Organ 

 der Amphibien. Morph. Jahrbuch, xxiii. 



EXPLANATION OF PLATES. 



Plate IV. Nine consecutive sections of the nasal region, fig. 1 being 

 a short distance behind the external narial opening, fig. 9 passing 

 through the internal nares. 



Plate V. A, Dorsal, and B, Ventral veins of a reconstruction of 

 the nasal apparatus of Pijxi americana. In B is shown in outline the 

 limits of the internal cavity ; while in both figures the planes of the 

 sections shown in Plate IV are indicated. 



ABBREVIATIONS. 



:Jacobson's organ. 

 : lateral nasal canal. 

 : nasal canal. 

 : branch of nasalis. 

 olfactory nerve. 

 : cavum nasale. 



: external portion of the nasal canal. 

 : Jacobson's gland. 

 : Jacobson's duct. 

 : posterior blindsac. 

 : difl'erentiated gland. 

 :naso-lachrymal duct. 

 = branch of olfactory nerve to Jacobson's organ. 



