284 ZAGLOSSUS. 



VISCERAL ANATOMY. 



Digestive tract. — As long ago as 1877, Paul Gervais pointed out that 

 the tongue of the Proechidna was much more highly developed than that of 

 the Echidna, in correlation with the greater development of the beak. Its 

 length he gave as 270 mm., while that of the Echidna was but 85. The horny 

 papillae at its base are differently disposed, and its anterior portion which is 

 trough-like is provided with three longitudinal series of spines, one median 

 and two marginal, whereas the tongue of Echidna is smooth save at its base. 

 The tongue of an adult Proechidna in the material studied, is 290 mm. long, 

 of which the three rows of horny points, backwardly directed, occupy the termi- 

 nal 80 mm. Of these points there are about 20 in the median and 22 in each of 

 the lateral rows. The portion of the tongue bearing these points is flattened, 

 with the margins slightly inrolled. Back from this tip, it is cylindrical and 

 increases to a diameter at its base of nearly 14 mm. There is a patch of scat- 

 tered horny papillae, backwardly directed, at the very base of the tongue. 

 The tongue of a young individual is but 85 mm. in length and there are only 

 15 horny papillae discernible in each row at the tip of the tongue. 



This young individual shows a series of -palatal papillae in the midline 

 of the rostrum. These are likewise directed backward, and the largest measure 

 about 2 mm. in length. The first eight are each divided by a median furrow 

 into a right and a left half. In the first six of these each half is secondarily 

 divided into three minute lobes, one anterior and two posterior, but in the two 

 following, the two posterior points are reduced to one. Farther back, the ninth 

 to twelfth are single median papillae, and decrease regularly in size till the last 

 two are almost unperceptible except as small rounded prominences, the last 

 about opposite the middle of the orbit. At the posterior end of the palate are 

 three transverse rows of horny, tooth-like papillae, the first of seven, the second 

 of ten, the third of nine. These rows are about 4 mm. apart. In an adult 

 specimen Gervais (1877-'78) describes five rows of these processes. 



I can add nothing to what has previously been published on the salivary 

 glands of the Proechidna. Viallanes (1879, 1880) has described the large elon- 

 gate and flattened submaxillary glands which are very conspicuous in both the 

 Echidna and the Proechidna. The terminal portion of the duct of these glands 

 is larger in the latter, and reaches from the base of the tongue to the symphysis 

 of the lower jaw. It expands into a fusiform reservoir with very glandular 



