10 CONTENTS OF A BONE CAVE. 



a right femur with patella, shafts of various long bones, fragments of pelvis and 

 maxillary bones, with three molars, and two partially complete, and other much 

 broken incisors. The teeth were scattered among the bones, and are so related in 

 size to most of them as to induce the belief that they all belong to the same ani- 

 mal. This is strengthened by the entire absence of bones or fragments which 

 could be referred to any other animal. 



Having requested Dr. van Kijgersma to make further search in the cave excava- 

 tions, that gentleman made an especial expedition to Anguilla for that purpose. 

 His efforts were rewarded by the recovery of ten or more teeth of the inferior 

 series, and a number of the superior molars of two individuals with various bones. 

 Teeth of five individuals of the species have probably been obtained in all. Dr. 

 van Kijgersma on subsequent expeditions obtained the other species, A. quadrans 

 and A. latidens. 



Of the first individual, three superior molars are preserved, which present four 

 dentinal columns. These columns are transverse, the first, which I assume to be 

 anterior, transverse ; the second, the longest ; the third, shortened inwardly and 

 slightly curved round the very small fourth, which occupies a postero-external 

 angle of the crown. All are separated by rather thick enamel laminae. The form 

 of the crown of the largest presents two sides of a square anteriorly and externally ; 

 the inner side bilobed in correspondence with the two anterior columns; the poste- 

 rior strongly convex backwards and outwards. The other, similar molar, differs in 

 the posterior outline being more nearly transverse, and the anterior and interior 

 outlines being united by a continuous curve. The large portion of the third tooth 

 preserved is perhaps the external ; it is part of a nearly regular transverse oval. 



The first described molar is strongly curved posteriorly, and its diameter narrows 

 regularly to the contracted base ; there is a shallow groove at the junction of the 

 anterior enamel lamina with the inner wall. This groove is much more strongly 

 marked in the second described, but ceases before attaining the contracted extrem- 

 ity. The shank of the tooth is less curved than in the other. The contraction is 

 less graded than in the first, but is strongly marked at the base, where the pulp 

 cavity is not wider than one of the columns. 



Lines. 



Length of anterior face, No. 1 (on curve) . . .14.3 



Diameter of crown (longitudinal) ... .6 



" " (transverse) . . . .5.7 



" of root (longitudinal) .... 4 



Length of anterior face, No. 2 ... 



Diameter of shank (longitudinal) 



" " (transverse) . . 5 



A portion of one of the inferior incisors of some forty-six lines in length, and 

 another shorter piece, furnish characters of the species and genus. The inner face 

 of the tooth is plane, and at right angles to the anterior ; the outer is rounded 

 obliquely inwards ; the inner face is broad and not prolonged ; the curve of the 

 tooth is in one plane, and the depth is about equal to the width. A narrow fold 

 of the enamel embraces the anterior border of the inner and outer faces; it is folded 

 back at a right angle within. 



