MUSEU.M OF COMPARATIVE ZOOLOGY. 153 



the first endoturbinal, and is compressed medio-laterallj. It is slightly 

 convolute outward at its base, and concave on its lateral surface. The 

 first endoturbinal is abruptly aciuninate anteriorly, and sti'aight on its 

 median, lateral, and under free siirfaces, the last named being concave 

 inferiorly. The second endoturbinal plate is oblique, and slightly in- 

 flated at its anterior end. Its lower border forms the inferior edge of 

 the median series of plates. The third endoturbinal is triangular in 

 shape, and is one half the size of the preceding. 



In ul. cinereiis the general plan resembles that of the foregoing species. 

 The parts are, however, of greater height, the interval between the first 

 and second endoturbinals being wider. The second endoturbinal is rela- 

 tively larger, and curved outward. This arrangement causes the plate 

 to present a concave surface outward, which receives the swollen lower 

 border of the third plate. The median aspect of the first endoturbinal 

 is straight ; bitt the lateral sui'face is deflected outward, and is impressed 

 on its entire surface by the ectoturbinal which rests upon it, leaving only 

 a raised rim of the endoturbinal round its anterior half The median 

 surface of the produced portion of the first endoturbinal is nearly as 

 high as it is long. The concave under surface embraces securely the 

 maxilloturbinal. 



Ni/dicjus crepuscular is. — In this genus the encranial surface is about 

 one third the area of the entire region, the cribriform plate marked as 

 follows : first, a single opening is seen on the sphenoturbinal surface ; 

 second, two openings on the ectoturbinal surface ; third, a relatively 

 large depression on the endoturbinal, containing two openings, well to 

 the lateral aspect, for the first endoturbinal plate. 



The nasal surface exhibits a single ectoturbinal plate. It is a little 

 less than one half the length of the first endoturbinal, is directed 

 almost vertically downward, the swollen upper border looking outward. 

 The lateral surface is concave, deflected outward as far as the tip of the 

 first endoturbinal. It is slightly concave above. The free portion is 

 acuminate, reaching as far as the level of the canine tooth. The sec- 

 ond plate is as in V.fiiscus, but not so much narrowed at the base. The 

 third is a mere rounded nodule. 



Lasinni/cteri." noctivagans. — The scptoturbinal space extends a little 

 ia advance of the septal line. There is but a single opening for the 

 ectoturbinal. The main plate is marked by a relatively small opening, 

 behind which extends a row of three small foramina. The non-perforate 

 space is as in the preceding forms. On tlie nasal surface the endoturbinal 

 series is inflated, and does not exhibit the lateral concavity seen in other 



