616 MR. E. B. POULTON ON THE [DeC. 18, 



tweeu the anterior and posterior circumvallate papillae. The posterior 

 is very large and shows perfect radial symmetry, exactly resembling 

 the ordinary papillae of higher mammals as seen from the surface ; 

 it is placed some distance behind the anterior papillae, as in Be- 

 lideus &c. The anterior papillae are small, but quite distinguishable 

 from above ; they seem to retain very little (if any) bilateral 

 symmetry and forward direction. To be certain on this point, 

 sections are necessary. The great development of the posterior 

 papillae in Marsupials, where there is any difference between the 

 three, compares in an interesting manner with the condition of many 

 higher mammals. In these latter it is quite common (e. g. in many 

 Insectivora &c., &c.) for the posterior papilla of the triangle to be 

 altogether lost, and for the tongue only to possess two papillae on the 

 same level ; these two obviously represent the anterior papillae, for 

 in allied species (e. g. the Hedgehog among Insectivora) the triangle 

 is complete. The three circumvallate pajiillae of Acrohates are placed 

 on a depressed smooth area at the back of the tongue. Imme- 

 diately anterior to the two foremost papillae the coronate surface 

 begins with a sudden transverse rise riglit across the tongue, thus 

 sheltering the circumvallate structures. There is a distinct normally 

 placed lateral organ beneath the fihform papillae, which is interesting 

 in its possession of only two furrows (as far as I can tell from surface 

 examination) ; these are distinct and well developed, and surrounded 

 by prominent lips. The coronate papillae are as abundant as usual 

 and have the ordinary arrangement. Fungiform papillae are very 

 common on the upper surface as well as on the sides. 



On the underside of the free part the ridge and grooves are 

 normal. The pointed tip of the organ is not turned down, suggest- 

 ing that the figure of Beliclei/s (fig. x. Plate LIV.) is correct. It is 

 extremely interesting that (as in the young marsupials and in Cetacea) 

 the epiglottis can be made to protrude through a notch in tlie soft 

 palate, so that breathing can go on uninterruptedly during the time 

 that the animal is drinking the sweet juices of the flowers of 

 Eucalypti, which constitute its food. The epiglottis is long and 

 tubular, and its opening is prolonged into a sHt posteriorly, so that 

 it must be a great protection at all times, and a perfect protection 

 when it is thrust through tlie notch, as I found it in this specimen. 



The soft palate is continuous with the pharynx laterally for a 

 long distance backwards ; its free edge is a deep mesial notch, of 

 which the anterior convex edge is just over the tubular epiglottis, 

 and of a size and shape that the latter fits completely. The fluids 

 (as in other cases) must pass on each side of the epiglottis. 



This tongue obviously belongs to the Phalangista and Belideus 

 type, and is a more complete specialization in the same direction than 

 is met with in these latter. 



The Tongue of Perameles nasuta. 



I have already described the general appearance and histological 

 details of this tongue in the ' Quarterly Journal of Microscopical 



