88 APODA 



CHAP. 



snakes, curiclatt'd with an asyninietrical development ui' tlie 

 lungs ; the left is reduced, while the right is drawn out into a 

 long cylindrical sac. The liver is likewise very long, and pai'tly 

 constricted into a great number of lobes. Owing to the great 

 reduction of the ribs progression is effected in an almost earth- 

 worm-like fashion l>y the peristaltic motion of the skin, assisted 

 by its numerous ring-shaped constrictions. 



The systematic position of the Coeciliae has been, and is 

 still, a controversial matter. The Sarasins took up Cope's 

 suggestion, that their nearest allies are the Urodela, especially 

 Amjjhmma, and they went so far as to look upon Amjjh'iuma as 

 a neotenic form (jf the " Coecilioidea," which they divided into 

 Amphiumidae and Coeciliidae ; the Coecilioidea and Salaman- 

 droidea forming the two sul)-orders of the Urodela. They based 

 this startling conclusion chiefly upon remarkable resemblances 

 between Amphiuvia and IcJitJtyoi^Jns, namely, (1) the mode of 

 laying the eggs on land and coiling themselves around them ; 

 (2) the existence of remnants of a tentacular apparatus in 

 Amphiumn ; (3) Cope's statement that AmpMviiia alone among 

 the Urodela possesses an ethmoid like the Coeciliae. This latter 

 point is, however, erroneous ; it has since been shown Ijy Davison ^ 

 that Ampliivma possesses no ethmoid bone, but that, instead of it, 

 descending plates of the frontals join below the premaxilla and 

 function as a nasal septum, with a canal foi- the olfactory nerves. 



We look upon the Apoda with more reason as creatures 

 which of all the Lissamphibia have retained most Stegocephalous 

 characters and at the same time form a highly specialised group 

 equivalent to the Urodela and the Anura. The following are 

 Stegocephalous inheritances peculiar to the Apoda in opposition 

 to the other recent Amphibia : retention of cutaneous scales 

 with calcareous incrustations, greatly resembling the scales of 

 the Carboniferous Microsauri ; occasional retention of post- 

 frontal and lateral nasal or lacrymal bones, and of a second row 

 of teetli in the mandible. To these may be added the presence of 

 epiotic bones, and tlie primitive character of the branchial arches. 

 The loss of all tliese characters would turn the present Apoda 

 into limbless X'^rodela, but this assumjjtion does not justify their 

 inclusion in this Order. The possible liomology of tlie tentacular 

 apparatus has been discussed elsewhere, p. 45. 



1 J. Moi-phol. xi. ISSlfj, p 'ilh. 



