152 PATAGONIAN EXPEDITIONS I PALAEONTOLOGY. 



MEASUREMENTS. 



Cephalic shield, length 1 30 Skull, extreme length 175 



" " width 133 Cranium, length to rim of orbit 125 



Upper dentition, length 109 Face, length 053 



J-, length (*.<?., antero-posterior diameter) .008 Cranium, width over zygomata 135 



" width (i.e., transverse diameter) 004 " " at postorbital constriction .049 



a , length 009 Forehead, width at postorbital processes . . .090 



" width 0055 Occiput, height 043 



, length 012 " width at base 087 



" width 007 Zygomatic arch, extreme length 098 



*, length 01 25 " " greatest dorso-ventral 



" width 008 width 028 



, length 0145 Zygomatic arch, length of suborbital process .045 



" width 008 " " distance between suborbital 



A, length 015 processes 1 1 1 



" width 0085 Rostrum, length 043 



1, length 014 " width at base 063 



" width 0085 " " " anterior end 041 



A, length 0135 Palate, length in median line 117 



" width 008 " width at * 014 



Skull, length in median basal line 156 " " " 025 



EUCINEPELTUS CRASSUS Sp. nOV. 

 (Plates XXI, Fig. 2, XXVI, Fig. 9.) 



The type and only known specimen (Princeton Mus. No. 15,865) is un- 

 fortunately very incomplete ; it consists of the cephalic shield, a few plates 

 of the carapace, an ungual phalanx of the manus and several bones of the 

 pes. The characters of the species are given by the cephalic shield (Plate 

 XXI, fig. 2), which differs from that of the other two species in shape and 

 in the number of plates which compose it. This number is fifteen, 

 instead of eleven, and the transverse rows have the following number of 

 plates, counting from before backward ; two, two, five, four, two. The 

 foremost pair of plates are very small and somewhat asymmetrical, that 

 on the right side being distinctly the larger of the two. These scutes 

 appear not to be represented at all in the other species, in the type- 

 specimens of which the shields were found in place and with anterior 

 margins entire, not indicating that the plates in question had been broken 

 away. The other additional plates are found in the third row, which thus 

 numbers five, instead of three as in the other species ; these additional 

 plates are of triangular shape and extend the lateral, wing-like processes 

 of the shield, giving them a greater antero-posterior extension than in 



