OPHIOMORPHA. 123 



semigelatinous remains of the notochord ; (2) the form and 

 structure of the skeleton; (3) the mode of implanting 

 teeth ; and (4) the articulation of the jaw and cranium. 

 But they are unlike fishes in, (1) the presence of two oc- 

 cipital condyles; (2) the nostrils opening into the mouth; 

 (3) the presence of lungs; (4) the absence of branchiae in 

 the adult. 



Again they are very similar to worms, (1) in respect 

 to their viscid, damp, slinry skin; (2) their forms and cu- 

 ticular folds; (3) their habit of boring into the ground in 

 damp places; (4) their food, vegetable matter, earth and 

 sand having been found in their intestines, but the pres- 

 ence of a vertebral column, and a cerebro-spinal nervous 

 system at once forbids their being grouped with this 

 class. 



Taken as a whole they seem to be possessed of a quin- 

 tuple nature, that is, they are related to the Amphis- 

 baenag, Ophidia, Pisces; Vermes, and the true Batra- 

 chia. Certainly the discovery of gills places them 

 among the last, though they will always be interesting 

 from their resemblance to the others. They furnish but 

 another illustration of how close is the union between the 

 cold-blooded vertebrates, and how artificial is the best 

 classification of the naturalist. 



In endeavoring to subdivide this family we find four 

 genera commonly recognized. The following table, tak- 

 en with slight changes from the British Museum Cata- 

 logue, will enable any one readily to refer an individual 

 to its appropriate place: 



