;[36 Trans. Acad. Sci. of St. Louis. 



series of teeth on the roof of the mouth borne on the pterygoids and 

 palatines. Several supranasals. Nostrils lateral, opening through a 

 single plate. Sternal bones represented by rudimentary cartilages; 

 clavicles not meeting at the middle line. Pelvis rudimentary and car- 

 tilaginous, the cartilages of opposite sides not meeting at the middle 

 line, each bearing a minute cartilage representing femora. (Garman.) 



39. Ophisaurus ventralis Linn. Glass Snake. Joint 

 Snake. 



Anguis ventralis, Chawaesaura ventralis, Hyalinus ventralis, OpMsau- 

 rtis punctattcs, Ophisaurus striatulus, Ophisaurus lineatus, Caecilia 

 maculata, Opheosaurus ventralis. 



Description. — Head continuous with the body, compressed forwards 

 and pointed. Two series of superciliary plates. Frontal large, widest 

 behind. Two small frontoparietals. Two large parietals and a pentag- 

 onal interparietal with a small whitish spot, the "pineal eye." Two 

 prefrontals. Internasal large, as broad, as long. Seven supranasals. 

 Nasal plate small, perforated by the nostril. Rostral slightly wider 

 than high. Eleven supralabials, the ninth and tenth largest. Mar- 

 ginal series of infralabials elongate and narrow. 



Ears a short, longitudinal slit of varying size, in line with the 

 mouth and lateral groove. Palatine teeth present. The pterygoid 

 teeth in three to five longitudinal series. Teeth all conical. Body long 

 and slender. Scales equal in size above and below, those on the poste- 

 rior part of the body and on tail with a slight median ridge forming 

 obtuse carinae. A deep groove extending from a short distance be- 

 hind the ear along the sides of the abdomen to the vent. Sixteen rows 

 of dorsal scales.. Ten rows of ventral scales. Seven or eight preanal 

 scales a little larger than the abdominals. 



Garman gives the arrangement of the sternal and pelvic bones as 

 follows: "The rudimentary sternal bones are imbedded in the muscles 

 a short distance behind the head. The sternum is a thin, transversely 

 elongate plate of cartilage, and lies behind the other bones of the arch. 

 The scapula is largely, perhaps wholly, bone. The supra-scapula is well 

 developed and is cartilaginous. The coracoid is large, transversely 

 placed, and meets its fellow of the opposite side; it is also cartilaginous. 

 The clavicle is a slender, curved bone, which is attached at its outer ex- 

 tremity to the ventral surface of the supra-scapula. 



"The pelvic bones consist of a rather long ilium, attached to the trans- 

 verse process of the fifty-seventh vertebra, and a flattened l)one, sup- 

 posed to represent the ischium and pubis combined, at its free ex- 

 tremity. In a small acetabulum in the surface of the latter fits a minute 

 cylindrical femur. The bones are fully ossified. Those of the two 

 sides are separated by a considerable interval. They are imbedded in 

 muscle slightly in front of the vent. The rudiments are probably quite 

 variable." 



