l66 rUCKERMAN. [Vol. IV. 



Spread over the lamellae is a thin layer of stratified pavement 

 epithelium, which usually fills up the depressions between them 

 to one level. Serous glands are plentiful in this region of the 

 tongue, and their ducts, which are exceedingly numerous, open 

 at the bottom of the furrows. The bulbs are disposed, midway 

 between the superior and inferior limits of the lateral wall of 

 the folds, in four to six closely set tiers. Each tier contains 

 about sixty bulbs in its entire length, I have counted as many 

 as eighty in a tier, but this number is largely in excess of the 

 mean. The dimensions of the bulbs are the same as in the cir- 

 cumvallate papilla. The fungiform papillae, particularly those 

 of the tip of the tongue, contain bulbs. I have not infrequently 

 seen six in a single section of a papilla of this type. The epi- 

 glottis was not examined, but bulbs have frequently been found 

 on the posterior surface of this organ in Leporidae, not only by 

 the present writer, but by Krause, Davis, and others. 



The Tongue of Geomys bjirsarins. 



The material consisted of a single spirit specimen. 



General Description. — The organ is compressed laterally to 

 fit the narrow mouth cavity, and is somewhat humped up ante- 

 riorly and posteriorly. It measures 26 mm. in length, 6.6 mm. 

 in breadth, and 9.5 mm. in thickness, and is quite free for 13 mm. 

 from the fraenum. The tip is drawn out into a rounded point. 

 The dorsal surface is covered with recurved filiform papillae. A 

 shallow median groove runs along the under surface. Fungi- 

 form papillae are not numerous, but occur upon the lower as well 

 as upper surface of the organ. There exists but one papilla of 

 the circumvallate type. It is set directly in the median line, 

 and very near the base of the tongue. The trench, both 

 anteriorly and posteriorly, is incomplete. It is anteriorly incom- 

 plete in Fiber zibethiciis. The lateral gustatory organs lie below 

 the convex surface of the posterior elevated portion, and some- 

 what anterior to the circumvallate papilla. 



Gustatory Structures. 



The Circumvallate Papilla. — The papilla measures 0.60 mm. 

 transversely, and is 0.35 mm. in height. At its upper part it 

 bears many secondary papillae, the depressions between them 

 being filled by the epithelium. Serous glands are plentiful, and 



