442 



EMBALLONl'EII.'iE. 



presence of a glandular gular sac. These characters appear suifi- 

 cienfc to unite them in a subgenus at least. But N. norfolcensis has 

 an additional upper premolar, which is even better developed than 

 in other species of the genus, and therefore belongs to the subgenus 

 Nycthionms ; while N. alhiventer and N. acetabulosus, on account of 

 the absence of this small premolar, are relegated to the subgenus 

 Mormo23terus. 



It is therefore impossible, in a natural arrangement of the spe- 

 cies, to separate iV. alhiventer and N. acetabulosus into a distinct 

 subgenus characterized by the number of the upper premolars, for 

 this would exclude N. norfolcensis, which is undoubtedly, in all 

 other respects, very closely allied to them, and forms with them a 

 well-defined section of the genus. 



Group MYSTACIN.^. 



The characters of the group are indicated under those of the 

 single genus below. 



14. MYSTACIWA. 



Mystaciua, Gray, Voyage of the ' Sulphur,' Mammalia, p. 23 (1843) ; 

 7omes, P. Z. S. 1857, p. 138. 



Ears separate ; the inner margin of the ear-conch arising from 

 the side of the head, the outer margin commencing opposite the 

 inner, not carried forwards on the side of the face ; tragus long, 

 attenuated ; muzzle obliquely truncated as in Molossus ; the nasal 

 apertures oblong, vertical. 



Middle finger of three phalanges, whereof the first is flexed down- 

 wards and forwards upon the metacarpal boue (in repose) ; legs 

 short, with well-developed tibite and fibulae as in the Molossi ; outer 

 and inner toes larger than the other toes ; tail perforating the inter- 

 femoral membrane and appearing upon its upper surface. 



Dentition. Inc. |, c. y^, pm. ~^, m. y^. 



Upper incisors largo, in the centre of the space between the 

 canines ; upper premolars well developed. 



This genus, represented by a single species only, unites some of 

 the characters of the Vesjaertilionidw to those of the Emballonuridce, 

 and in the latter family connects the subfamUy Emhallonurince with 

 the MolossincB. 



1. Mystacina tuber culata. 



Mystacina tuberculata, Ch'ay, Voyage of the 'Sulphur,^ Mammalia, 



p. 23 (1843) ; Vol/, of the 'Erebus' and' Terror,' iv. pi. 22 (1844) ; 



Tomes, P. Z. 8. ' 1857, p. 138, pi. liv. ; Dobson, P. Z. 8. 1876, 



p. 486, figs, a, b (thumb and foot). 

 Mystacina velutina, Hutton, Trans. New-Zeala/id Institute, iv. p. 185 



'(1H71). 



Crown of the head rather abruptly imt slightly elevated above the 



