RHACHITOMOUS VERTEBRAE 587 



fused vestige. For this reason I abandon the term procoracoid 

 and adopt the terms metacoracoid and coracoid, or epicoracoid 

 if one desires a distinctive name for the anterior element, after 

 Howes and Lydekker, the former of whom reached the same 

 conclusion from the study of the mammals. 



Araeoscelidae, family new. 



Araeoscelis gracilis, genus and species new. 



This species is represented by numerous remains found asso- 

 ciated in a space of a few square feet, including various limb bones 

 and vertebrae found free in the clay, and three or four more or 

 less complete skeletons imbedded in clay nodules — in a more or less 

 disturbed condition. There are parts or wholes of four or five 

 skulls among them, but unfortunately their delicacy is such that 

 they are more or less distorted and only by a careful preparation 

 with needle and lens can one hope to determine their characters. 

 This much however may be said: The teeth are placed closely 

 together and are of uniform size, obtusely pointed as seen from the 

 side, with their bases rather wider than long; there is but a single 

 row. There is a row of slender conical teeth on the palate. The 

 orbits are large, and almost certainly there is a single large temporal 

 vacuity. The skull is lizard-like in shape, in the smallest about 

 30 millimeters in length; in the largest about 50. 



The vertebrae, of which there are numerous free examples in 

 the collection, in addition to several more or less complete series, 

 in the nodules, are remarkable for their slenderness and delicacy. 

 The dorsal vertebrae (Figs. 13, 17) are elongate, narrowly keeled 

 below, with a rudimentary spine in front; there is a short diapo- 

 physis just back of the front zygapophyses ; and intercentra are 

 present. 



The ribs, of which there are numerous free representatives, are 

 rather stout and single headed — a unique character if it is repre- 

 sentative of the whole dorsal series. The caudal vertebrae (Plate I, 

 Figs. II, 12) are remarkable for their great elongation and slender- 

 ness, having a slender carina on the under side, and a small parapo- 

 physial facet on each side in front, for the attachment of ribs, 

 another remarkable character. The pectoral and pelvic girdles 

 are present in at least two specimens, but are scarcely visible in 



