618 REPORT OF NATIONAL MUSEUM, 1898. 



Ilium directed slightly forward and upward, and articulating by its 

 proximal extremity with the fused distal extremities of the diapo- 

 physes of two vertebra?. Posterior limb exactly like the anterior, that 

 is, consisting of a proximal element (femur) and a distal rudimental 

 segment. 



Fiirbringer' describes and figures the shoulder and pelvic girdles 

 of Acontias meleagris and A. plumbeus. The shoulder girdles consist 

 of simple elements supposed to represent scapula?, fused or not on 

 the middle line, the median portion of which, in the A. plumheus, it 

 is suggested, may be clavicles. The pelvic girdles consist, in both 

 species, of a simple element on each side, consisting of ilium (joined 

 to vertebra?) and supposed pubis. My examination of Evesia shows 

 the impropriety of combining that genus with Acontias^ as has been 

 done by Boulenger. 



As in other families, in the serpentiform types the liver and stomach 

 occupy a position caudad to the lungs, and so the latter do not appear 

 in the mesenteric connections of the former; as, for instance, Siajyhos. 

 The mesenteries are the usual ones, but one peculiarity is very fre- 

 quent, though not universal in the family. The hepatoventral sheet is 

 generally divided into two, a right and a left sheet, next the liver, 

 forming a pocket, which opens caudad. In the Tiliqua scincoides the 

 two sheets only unite at the cephalic end of the liver, remaining sepa- 

 rate throughout. 



Dr. Boulenger remarks as to this family: 



I have met with great difficulty in arranging the genera of this family. The 

 majority of the characters hitherto employed for the distinction of genera, such as 

 the degree of development of the limbs, the jiresence or absence of a transparent 

 disc in the lower eyelid, the presence or absence of keels on scales, etc., are in many 

 cases not even of specific value. I have therefore used certain characters which 

 hitherto have been neglected, but which, I am convinced, afford a firmer basis for a 

 natural arrangement. The artificial nature of an arrangement based on the degree 

 of the development of the liml)8 has been pointed out by others. In a family like 

 the Scincoids, in which the limbs are undergoing a process of abortion, this charac- 

 ter must be abandoned as one expressing relationship bj^ itself. And I trust that 

 the arrangement of the species in one or more series within a genus, passing from 

 forms with well developed pentadactyle limbs and lacertiform physiognomy to such 

 as have rudimentary limbs, or even none at all, marks a great improvement upon 

 the artificial classifications in use down to the present day. 



I am not prepared to admit that the above remarks of Dr. Boulenger 

 have more than au application to the cases where the development of 

 the limbs and digits is irregular in the same species. This has not 

 been shown to be the case more frequently than we expected to find in 

 all other zoological characters, and particularly those which we call 

 generic. It is indeed precisely the grades of characters expressed by 

 the last structural modification of parts that the generic nomenclature 

 is created to record. So long as the characters are constant then it is 

 necessary to designate them by generic terms, and I have therefore 



iKnochen und Muskeln Schlangeniihulicher Saurier, Leipsic, 1880. 



