Mr. H. F. Tonics on the genus Nyctophilus. 377 



TIk- orirans of flif^ht so exactly resemble those of the genus Vesper- 

 til m, tlmt it 13 net'illcss to make further remarks on them, excepting 

 to mention tliat the wing-meinl)ranes sjiring from the base of tlie toes. 



AH the hinder extremities may be similarly dismissed. 



The cranium in its general appearance resembles that of several 

 species of Vespertilionidce, and so nearly, that it would be easy at 

 first sight to confound them. The Serotine Bat of Euroj)e, the 

 Scotop/iilus Carolinensis and Vespertilio t'c/a^u* of America, but more 

 especially a species inhabiting the same country as the Nyctophdus, 

 viz. J'esp. Tasniunieiisis, may be cited as species, the crania of which 

 are most like that of Xi/ctop/iilus. 



The cerebral portion is but little elevated above the facial portion, 

 and it rounds off but very little from the vertex to the occiput, above 

 the foramen of which is a moderately developed occipital crest, vary- 

 ing considerably in different species. There is the same deep notch 

 in the anterior part of the skull which is observable in Vespertilio 

 and Scotophilus, caused by the imperfect development of the inter- 

 maxillary bones. Immediately above this notch is a rather broad 

 but shallow depression, occupying the position of the nasal bones. 

 It is as deep from side to side as from before to behind ; but there 

 is one point where it runs a little deeper than elsewhere, just at the 

 hinder ends of the nasal bones. Precisely the same kind of depres- 

 sion occurs in the cranium of the Barbastelle But. But in Xycto- 

 philns the depression is rendered more conspicuous by the somewhat 

 more elevated position of the malar processes. 



The zygomatic arches are not very much arched outwards, less so 

 than in many species of Vesjyertilio, such as V. Nattereri, but quite 

 as much so as in Plecotus. The orbits extend rather markedly for- 

 ward, in one species almost to the root of the canine tooth, whilst 

 the palatal portion of the maxillary bones reaches as far back as 

 usual, so as to give a somewhat greater extent ofj/uor than ordinary 

 to the orbit. The bony palate extends backwards almost to the con- 

 dyloid fossa ; but its hinder margin is so much scooped out that its 

 middle does not much exceed the middle of the zygomatic arch, in 

 a backward direction. In this respect it resembles the same part in 

 Plecotus ; in Barbastellus, Vespertilio, and Scotophilus it is doubly 

 emarginate. 



The teeth of the upper jaw, when seen from below, present two 

 straight lines, somewhat diverging towards their hinder ends, just as 

 in Vesp. velatus, Scot, serotinus, Scot. Carolinensis, and Barba- 

 stellus. The two incisors are the only teeth which deviate from these 

 lines, being placed more inward than the canines, which terminate 

 them. Seen laterally, the upper teeth have a curved outline, bend- 

 ing slightly upward from the root of the zygoma to the most anterior 

 part of the intermaxillary bone. The exact form of the lower margin 

 of the maxillary and intermaxillary bones is tolerably well indicated 

 by the range of the teeth, as just stated ; and it may be here re- 

 marked, that this is a point worthy of attention in the classification 

 of the Vesper tilionidte. 



