3897.] SKELETON OP PELODTTES ITNCTATUS. . 583 



consensus of opinion (Duges (4), Gcitte (6), Schuize (18), and 

 others) is that it represents the " basihyal." jS'ot wishing to 

 enter upon an exhaustive and possibly futile discussion of the 

 morphological value of this part, 1 accept the latter determination 

 and call the median plate of cartilage {hh., fig. 1) the basihyal. 

 This median cartilage is connected with two pairs of large lateral 

 cartilages, the so-called " ceratohyals '' ^ in fi^ont and the branchial 

 plates behind. The ceratohyals {cJi., fig. 1) stand out nearly at 

 right-angles to the long axis of the body, and slope but slightly 

 backwards. Their distjil ends articulate by an obliquely elonga'-ed 

 convex surface {ha., fig. 1) with the under surface of the palato- 

 quadrate cartilage. The internal or mesial extremities are broad 

 and flat, with a delicately curved inner edge, and are united 

 together in front of the basihyal by a broad band of iibrous tissue 

 (the "queres, fibroses Band" of' Eathke, 14. p. 1.32, Pseudis 

 paradoxa ; and the " pars reuniens " of Gaupp, 5, Rana fusm). 

 In front of this is the hyoglossal notch, at present V-shaped, but 

 later semicircular. 



The branchial skeleton consists of two branchial plates, riglit 

 and left, attached to the posterior part of the basihyal, and in 

 contact with one another for a short distance in the median line 

 behind it. Each is connected, at about one-fourth of its width 

 from the median line, with the backvvardly projecting cusp of the 

 flattened part of the ceratohyal. The" small triangular space 

 (s, fig. 1) thus enclosed between the basihyal and the ceratohyal 

 and branchial plate of each side is filled with a loose connective 

 tissue, which only undergoes chondrification in Stage 4. The 

 antero-interual part of each branchial plate is on the same level as 

 the basihyal and ceratohyal, but the remaining grid-like portion of 

 the plate is deeply concave above. The four curved bars, the 

 so-called " ceratobranchials," are directed outwards and backwards 

 and are connected togetlier at their distal end by an irregular 

 marginal band of cartilage (" commissura terminalis " of Gaupp, 5 ; 

 " epibranchiale "of Schuize, 18) and at their proximal ends by the 

 common hypobranchial plate {hh:, fig. 1 ), The distal halves of 

 the ceratobranchials bear on their anterior and posterior surfaces 

 a series of four or five irregular, short, blunt outgrowths of 



^ I fail to see the practical utility of the introduction by Gaupp (5) of new 

 non-committal terms, such as byale, branchialia, and plan\im branchiale. It i s 

 doubtful, most anatomists will admit, whether the structures so designated 

 correspond exactly to the eeratoh.val, ceratobranchials, and hypobrancliTals of 

 the fish, and it would have been desirable if, in the first instance, less definitive 

 terms had been employed until the true lioraologies of the parts had been 

 determined. But now that the names have been in use for so long and are so 

 familiar, it is only confusing matters to attempt to replace them by names 

 more vague in their significance. When the implied homology has been 

 definitely disproved, when the so-called ceratohval of the tadpole has been 

 shown to be something quite diife-ent from the ceratohyal of the fish, and so 

 on, then will be the time for a radical change in our nomenclature. We are, 

 however, still in the dark with regard to the morphological significance of the' 

 Anuran hyobranchial skeleton, and the onus of the proof of the false homology 

 implied by the terms at present in use lies with the objectors. 



