MUSEUM OF COMPARATIVE ZOOLOGY. 157 



far as the anterior border of the first molar. The second plate is con- 

 cealed, and the third and fourth arc arranged much as in Vampyrops, 

 which this form in great part resembles. The lobule on the first endo- 

 turbinal is small, but readily discernible. The plates below their in- 

 flated summits are not clearly seen. The parts on the median surface 

 are contiguous. 



Vampyrops. — The ectoturbinal extends the entire length of the inner 

 wall of the orbit, and is inflated. The first endoturbinal is concealed 

 between the last named and the second endoturbinal. It is a simple 

 inflated plate, without convolutions. It is in intimate association with 

 the region of the second plate, with which it may be confounded. If 

 the first endoturbinal plate be counted as a lobule upon the base of the 

 second, the series will lack the number five which all other genera of 

 this group possess. Assuming, therefore, that the concealed plate is the 

 true second endoturbinal, the one below it becomes the third. The last- 

 named third plate is the largest of the series, and resembles the second 

 of the Pteroderma related forms. It is broad, non-convolute, and ends in 

 a narrow tongue that reaches a point as far forward as the anterior bor- 

 der of the first molar tooth. The fourth endoturbinal is a nearly simple 

 plate, having a thickened free upper border. Its free surface is entirely 

 median, and almost linear. The fifth endoturbinal is exposed on the 

 median surface for its entire extent ; its anterior border is thickened, and 

 convolute upwards. The frontal section of the ethmoturbinal presents 

 the ectoturbinal and the first endoturbinal in close juxtaposition and as- 

 suming a medio-lateral relation, while the remaining plates are am 

 nearly at right angles to them. There appear to be no plates compara- 

 ble to the sphenoturbinals. 



Pteroderma (Plate V. fig. G). — The ectoturbinal of a triangular form, 

 whose base is forward and advances as far as the ends of the olfactory 

 plates of the endoturbinals minus the lobules, ami nearly to the hinder 

 border of the orifice of the maxillary sinus. 



The first endoturbinal is couvolute laterally, and possesses an acu- 

 minate lobe directed forward that equals the plate itself in length. The 

 free end of Hie olfactory plate is distinctly seen beneath tin' level of the 

 lobe. Lying at the level of the lobe just described, behind the free por- 

 tion of the plate, is a small nodule, which may receive the name of the 

 posterior lobe, as opposed to the preceding, whioh is as compared to this 

 an anterior lobe. The second endoturbinal plate is free interiorly, hut is 



biconvolute above for the greater part of its length. The last-named 



portions are concealed by the lobes o{' the adjacent plates. The third 



