36 MILLER 



together tlian in the smaller animal. Antorbital foramen over anterior 

 extremity of second premolar and region of contact between it and 

 first. Pterygoids imperfect, but evidently further apart than in M. 

 redmani. Base of braincase as in M. redmant send j\I. portoricensis. 

 Presphenoid injured, but apparently as in these species and not like 

 that of JM. clinedaphus. Zygomata very lightly built, even more 

 slender than in M. portoricensis. Mandible about as long as that of 

 M. clinedaphus^ but more lightly built than in any of the know^n 

 members of the genus ; while distinctly longer than that of J/, por- 

 toricensis it is scarcely if any deeper. 



Measurements of skull of type : Greatest length 21.6; basal length 

 19.4; basilar length 17. S; zygomatic breadth 9.8; least interorbital 

 breadth 4.6; mastoid breadth 9.6; greatest breadth of braincase 

 10; frontopalatal depth (at middle of molar series) 2.4; depth of 

 braincase 6; maxillary toothrow (exclusive of incisors) 7.2; man- 

 dible 14; postdental portion of mandible 5.8; mandibular toothrow 

 (exclusive of incisors) ^.%. 



Teeth. — The teeth oi Monophyllus plethodon differ conspicuously 

 from those of the other members of the genus in that they are so 

 crowded that all trace of the characteristic space in front of posterior 

 premolar of both jaws is obliterated. This tendency to crowding is 

 also evident in the upper incisors, the innermost pair of which are 

 almost in contact, while in the three other species they are separated 

 by a noticeable space. Canines slender, relatively closer together than 

 in other members of the genus, their shafts parallel or a little con- 

 verge7it. Maxillary teeth otherwise essentially as in J/, redmani. 

 Mandibular incisors very minute, but normal in form and position. 

 First lower premolar distinctly longer than second, over which its 

 posterior edge is imbricated, much as in Af. portorice?isis. The re- 

 maining mandibular teeth do not differ conspicuously from those of 

 the other ntembers of the genus. 



Measurements. — For measurements of Monophyllus plethodon see 

 table, page 38. 



Speci?>iens examined. — One, the type. 



Remarks. — Monophyllus plethodon is immediately recognizable by 

 its crowded teeth and slender rostrum. 



MONOPHYLLUS CLINEDAPHUS sp. nov. 



Type. — Adult male (in alcohol) no. •jV-fiTS' United States National 

 Museum. No history. 



General characters. — See synopsis. 



