TEGUMENTS OF REPTILES. 



551 



367 



a lamellate structure, fig. 368, g, like that of Fishes, but with the 

 direction of the fibres, in succeeding layers, more regularly alter- 

 nating. In most parts of the trunk of the Anoura the skin is 

 separated by wide lymphatic lacunae, fig. 367, r, from the subcuta- 

 neous fascia, ib. E. Marsupial pouches, one for each larva, ib. b, c, 

 are temporarilydeveloped in 

 the skin of the back of the fe- 

 male Pipa : a common dorsal 

 pouch for eggs and larvae is 

 present in the female Noto- 

 trema marsupiatum, Gnth., 

 and in Opisthodelphys. The 

 epiderm in Perennibranchi- 

 ates resembles that of mu- 

 raenoid Fishes : in most A- 

 noura the constituent nucle- 

 ate cells are more condensed, 

 fig. 368, b : in many Toads 

 the epiderm is tuberculate ; 

 rarely are scales, and scutes 

 never, present in the exist- 

 ing Batrachia. In Ccecilia 

 the skin is ringed by trans- 

 verse rugae. In the Ameri- 

 can Newts, of the genus 

 Plestiodon, the small scales 

 present a reticulate struc- 

 ture. In Bufo tuberosus the epiderm forms on the dorsal tuber- 

 cles a horny spine in the centre, surrounded by a ring of 

 smaller spines : Bufo asper has conical spine-bearing tubercles 

 on the back and sides of the trunk : those on the upper eye- 

 lids of certain Toads have earned for them the generic name 

 Ceratopltrys {Bana cornuta, Linn.). In Salamandra unguiculata, 

 and in Dacti/lethra among the Toads, the epiderm is condensed 

 into a claw at the end of some of the digits : in D. Mulleri it 

 also forms a spur at the base of the first hind-toe. In Pipa the 

 skin is produced at the end of each fore-toe into a 3- or 4-forked 

 appendage, fig. 367. As a rule, the Batrachia are without claws. 

 Pigment-cells, fig. 368, a, are developed in various degrees, and 

 of diverse shades of colour, commonly of a dull and neutral or 

 mixed tint, but giving to parts of the skin of the land Salamander 

 a yellow or orange hue, and painting the surface of the Trec- 

 Frog (Hylci) a bright polished green. 



Female Pipa, or Surinam Toad. 



