DEVELOPMENT OF THE SKELETON OF THE TUATARA, 56 
Boulenger first showed him? to be probably in error. Baur, accepting Boulenger’s 
correction, has sought to show? that the bones regarded by him as the supra-temporal 
and squamosal lie within the area of the ‘‘ squamosal” of Sphenodon, and that that 
bone is therefore compound. Shufiling the terms, he regarded the body of the latter 
with its laterally visible processes as a “ prosquamosal ” (‘squamosal ” auct.) and its 
posterior ascending process as the squamosal (‘‘ supra-temporal ” auct.). 
Seeking for evidence in support of this in the Tuatara, Baur admits that none was 
forthcoming in a skull of 25 mm. in length (op. cit. p. 321). Not only have we failed 
in all attempts to detect any such separation, but also to observe at any period traces 
of a second element. While we fully admit that this so-called “ squamosal” of 
Sphenodon combines the structural relationships of the supra-temporal and squamosal 
as originally defined, failing the discovery of any trace of its supposed double nature, 
we are disposed, on consideration of the behaviour and all detailed relationships of the 
supra-temporal in the Lacertilia, to regard it as a squamosal, and to interpret its 
ascending limb, which meets the parotic process of the parietal, as secondarily acquired. 
The alternative would be the introduction of a new term, in which neither 
“‘squamosal’’ nor ‘“‘ temporal” were compounded, but we have no wish to render 
confusion more confounded. ‘The future can only settle the question, and we are 
content to leave it to that. 
The Quadrato-jugal.—This bone, as is well known, was first recognized in Sphenodon 
by Dollo %, and later more fully described by Baur*. We have nothing to add to their 
descriptive account of it. Its most characteristic feature is its enclosure with 
the quadrate (qu. & q,j., Pl. IV. figs. 7 & 9) of a conspicuous foramen. Osawa, the 
latest writer upon it, terms it (98*. pp. 499 & 520) the “tympanic,” presumably 
on account of his inability to regard the mammalian tympanic as the homologue of the 
quadrate; and associated with the study of this bone there is a matter of no little 
importance, if, as we believe, the tendency of our time is in error. 
Baur, in 1889, argued® against the generally accepted belief that the single 
Smith Woodward is not uniform in his terminology. Boulenger, onthe other hand, is so, and, like ourselves, 
he retains the terms for the bones to which they were originally applied—i. e. for him, in both fishes and 
reptiles, the inner is the supra-temporal, the outer the squamosal. Difficulty admittedly arises when but one 
bone is present, and there is no doubt that in many such cases the problem can only be solved develop- 
mentally ; but, on comparison of those lizards in which both bones are present, we believe him to be right in 
regarding the bone which alone suspends the quadrate in the Ophidia (Brit. Mus. Cat. ‘‘ Ophidia”) as the 
supra-temporal, and not the squamosal as do Huxley and his followers. 
" Boulenger, G. A.: Ann. & Mag. Nat. Hist. (ser. 6) vol. xi. 1893, p. 209. 
* Baur, G.: Anat. Anz. Bd. x. 1895, p. 322, ef. also Amer. Nat. vol. xxx. 1896, p. 145. 
* Dollo, L.: Bull. Mus. R. Nat. Hist. Belg. t. ii. 1883, p. 235, 
* Baur, G.: Zool. Anz. Bd. ix. 1886, p. 685. 
* Baur, G.: Journ, of Morphol. yol. iii. 1889, p. 473. 
