448 ^Ir. W. L. Byrne on a ncic Species oj 



tlie molars differ by facing furtlier outwards than usual, the 

 line of the two grinding-surfaces, if produced internally, 

 meeting at an angle almost approaching a right an^le, 

 i. e. about 110°. In //. chacaj-tus they meet at about 130°, 

 and in a large example of fl. vulpinus at over 150°. I cannot 

 find ihat there is any appreciable age-variation in this 

 character, though its exact definition is not easy. 



Dimensions of the type (measured in the flesh) : — 



Headandbody " 132'' mm.*; tail 133; hind foot 35-5; 

 ear 18. 



Skull: greatest length 35; basilar length 29*5; greatest 

 breadth 20 ; nasals 133 ; intcrorbital breadth 4'3 ; palatilar 

 length 18"2 ; diastema 10; palatal foramina 7*3; length of 

 upper molar series 7*5 ; breadth of m^ 2'5. 



Hah. Banado de S. Felipe, Tucuman. Alt. 435 m. 



Type. Female. B.M. no. 4. 10. 2. 5. Collected 18th June, 

 1904, by L. Dinelli. One specimen. 



This small species is remarkable for its thick and heavy 

 molars and the unusually oblique angle at which they are set. 



LXIX. — A neio Species o/ Pteridium (Scopoli) from the 

 Nort/i-east Atlantic. By L. W. Byrxe. 



Only a single species of Pteridium (Scopoli), as defined by 

 Giintherf ('Challenger' Deep-sea Fishes, p. 105), has 

 liitherto been described — P. atrum (Risso), a denizen of the 

 Mediterranean coast of France, where, however, it appears 

 to be uncommon. 



On a recent cruise in the northern portion of the Bav of 

 Biscay the S.S. ' Huxley,' employed by the Marine Biological 

 Association of the United Kingdom upon the International 

 Fishery Investigations, took a fish of this genus which 

 appears to be referable to a previously undescribed species, 

 which I propose to name in honour of my friend Dr. E. J. 

 Allen, the Director of the Association. 



Pteridium AUeni. 



Form stout; body compressed in caudal region, its greatest 

 height about 4 times in its length (without caudal tin). 



* This would appear to be an nnder-iueasuremont : the skin looks 

 contracted, but the head and body still meivsure over 140 mm. 



t The " some slifrhtly eularjred teeth alonur the inner series of the 

 mandible and on the vomer,"' mentioned by Ciiinther, are stated by 

 Moieau, on the authority of R-llotti, to be found iu the male only. 



