C'ROCODILIAXS, LIZARDS, AND SNAKES. 471 



I'aninienti DuMKKiLaiiil 15iiii:on, part, Eip. Gc-n., HI, 1836, p. 137. 

 Monitoridw Gkay, Aun. Nat. Hist., 1, 1838, p. 392; Cat. Liz., 184.5, pp. 3, 0. 

 Varanida' Copk, Proc. Acad. Nat. Sci., Thila., 1864, p. 227. 



Varanidw Boulexgkh, Ann. Mag. Nat. Hist. (5), XIV, 1884, p. 120; Cut. Liz. Brit, 

 Mus., 2(1 ed , II, 1885, p. 303. 



Characters of the skeleton in this family are the following: 



Premaxillary single, in contact with inaxillopalatiiies. Splenial 

 bone well developed, MeckeFs groove expo.sed; coronoid prodnced 

 anteriorly and not posteriorly on external face of ramus ; angular lit- 

 tle developed on inner, much developed on outer side of ramus; den- 

 tary not produced posteriorly. Supratemporal fossa not roofed by 

 ossitication. Nasal bones coossified. 



The visceral characters of Varanus, the only genus of the family, 

 aie unlike those of other genera of lizards. The heart and liver 

 occupy a more ijosterior position than usual, the heart being much fur- 

 ther posterior to the sternum than any other family, and adjacent to 

 the liver. The lungs do not partake in this peculiarity, since they 

 begin a considerable distance anterior to the heart and terminate 

 opposite the proximal extremity of the liver, instead of lying on either 

 side oj that organ and coterminous with it, which is the position in 

 other Sauria. 



Tlie trachea bifurcates well cephalad of the lungs, presenting nuich 

 longer bronchi than any other type. The aorta roots in like manner 

 make their posterior curvature anterior to the usual position. The 

 liver is bilobate at both extremities, but the right lobe is much pro- 

 duced distally into a striplike process, as in most other Sauria. The 

 gall-bladder is on the superior side of the liver within the posterior 

 border, and is not visible from below. The aliincntary canal is of mod- 

 erate length, and the small intestine is well specialized from the stom- 

 ach. There is no dilatation constricted off as a colon. Urinary bladder 

 and corpora adiposa present. The latter do not i)roject freely into the 

 C(elom, but lie between the peritoneum and the body walls. 



The peritoneal folds have the following distribution: There are two 

 gastrohepatio sheets, but the right is much shorter caudad than the 

 left. There is no sheet connecting the left lobe of the liver with the 

 body wall nor are there any connecting the distal border of the liver 

 with either body wall. A sheet, however, connects the right border of 

 the liver with the body wall. At the middle of the hepatic border 

 this sheet is single, but at the cephalad and caudad extremities it is 

 double, producing funnel-shaped sacs which open toward each other. 

 Ventral mesentery single, and not extending beyond liver, A strong- 

 sheet of peritoneum connects the pericardium with the body wall on 

 each side. 



The great ease with which the peritoneum is separated from the 

 body walls in Varan us has led authors to make some curious state- 

 ments. Thus Giinther says ' that the corpora adiposa are inclosed in a 



'TIio Anatomy o( Reytnia ocellalu, Vtoc. Zool. Soc. Loudon, Febriiary-Manh, 1861. 



