OCR Text |
Show 610 MR. E. B. POULTON ON THE [Dec. 18, gland-ducts were visible. The raphe, inferior median ridge and grooves, and the arrangement of the coronate papilla? are all exactly as in Macropus. Obviously this organ is very close to that of Macropus. THE TONGUE OF Basyurus maugai. Quite recently I received a fresh tongue of this species ; and I am very glad to be able to add the general description, because until now I have not had the opportunity of investigating this organ in any of the Marsupialia Sarcophaga, and I felt uncertain as to whether the previous observations (such as the existence of coronate papilla?) would hold. I was also much interested in ascertaining whether the organ was much modified by the very distinct change of habits, and in determining the relative resemblance of this organ to the other various types., The shape was not remarkable, the tip being simply rounded as seen from above and forming a rather sharp edge. The junction between the papillate and non-papillate surfaces was sharp and even ; the ridge and grooves as usual. There is a slight trace of a median raphe. The circumvallate papilla? form the usual triangle, which is here fairly equilateral, but the sides are a little shorter than the base. The papilla? seem to be bilaterally symmetrical, and their tall pointed apices are directed backwards. If this is the condition in the living state, it is unique as far as I have yet observed. The posterior papilla seems to be a little larger than the others. They are all studded with small protuberances (secondary papilla?) on the anterior side of the lowest part visible. The upper recurved part exactly resembles a large filiform papilla, and as these are common round the circumvallate papilla?, the suggestion arises that the available (otherwise unused) surface of the latter has been modified into the former. There seems to be no trace of a lateral organ. The fungiform papilla? are distributed as usual, extending round the tip and scattered over the whole upper surface in considerable abundance. The filiform papillae are long and also flaplike ; they are continued backwards and upwards from the usual position on to the area of the circumvallate papillae, as has been previously described in Perameles. Posteriorly the coronate papilla? seem to be transitional into the filiform papilla? by a relative increase in the posterior secondary papilla and a gradual disappearance of the rest of the ring (also noticed in Perameles and the same general tendency in many forms). The coronate papilla? seem to be well developed and of normal structure over the whole of the upper surface. Of course this can only be rendered certain by sections. Posteriorly in the middle line, just in front of the anterior circumvallate papilla?, it appears that the secondary papillae are much shortened, but traces of them can be made out. Thus upon the whole this tongue comes nearest to the Halmaturus type, in the possession of three bilaterally symmetrical circumvallate papilla?. But this conclusion is not certain, and may |