252 Illinois State Lahoratory of Natural History. 



in the last forty years by the felling of timber, cultivation of 

 the soil, and draining of ponds and swamp lands, has had its 

 effect upon our fauna, and the capture of a species in central or 

 northern Illinois forty years ago is not necessarily evidence as 

 to the present distribution of the species. Southern birds and 

 serpents v^^hich were in early days not rare in the latitude of 

 Bloomingtou and Peoria are now not found away from south- 

 ern Illinois, some of them not in the State at all. The food of 

 the brown swift consists of insects. The stomach of an exam- 

 ple from southern Illinois, dissected Jan. 12, 1885, was nearly 

 filled with small ants (Crematogaster), and contained besides, 

 two beetles (one a carabid, the other a chrysoraelid) and a 

 cricket. It is commonly seen on old rail fences or in the woods 

 on logs. It runs with great rapidity, and often eludes the col- 

 lector by scampering up the trunks of trees. 



Family ANGUID^. 



Legs wanting or two rudimentary posterior legs present. 

 Body long and serpentiform, with lateral longitudinal grooves. 

 Head pyramidal. Tongue bifid, extensile, with squamiform 

 papillae. Teeth placed on the inside of the jaws and project- 

 ing inwards. 



Ophisaurus, Daudin. 



Daudin, Hist. Nat. Kept., 1803, YII., p. 346. 

 Dum. et Bibr., Erp. Gen., 1839, V., p. 421. 

 Holbrook, N. A. Herp., 1842, II., p. 139. 



Legs wanting. Ear-opening present, small. Eyelids well 

 developed. A deep groove along each side of the abdomen. 

 Two longitudinal series of teeth on the roof of the mouth 

 borne on the pterygoids and palatines. Several supranasals. 

 Nostril lateral, opening through a single plate. Sternal bones 

 represented by rudimentary cartilages; clavicles not meeting at 

 the middle line. Pelvis rudimentary and cartilaginous, the 

 cartilages of opposite sides not meeting at the middle line, each 

 bearing a minute cartilage representing femora. 



The species described is the only one in the genus. 



