222 JIR. W. K. PARKER ON THE STRUCTURE AND 



by it, the nasals and the maxillaries (mx.), there is a roughly orbicular, notched septo- 

 maxillary {s.mx.). Tlic maxillaries (fig. 1, mx.) are large, deep, sculptured bones, with 

 both margins somewhat sigmoid ; the qiiadrato-jugals are unusually long, thick, and 

 broad ; they are strongly grafted on to the quadrate (q.). The suspensorium curs^es 

 forwards towards the large sulcate trochlea (</.c.). The inner process of the pterygoid 

 (fio-. 2, py.) binds the pedicle, the hinder process binds the inside of the quadrate, and 

 the front part, which is very wide, behind, shows a large tract of cartilage (•«/>.), and 

 is strongly bound to the inner face of the maxillary. The mandible (fig. 1) has a large 

 and deep articular process, the Meckelian rod {mk.) is scarcely affected by the half 

 sheath of bone — the articulare ; the dentary {d.) is only a third the length of the 

 ramus ; tlie mento-Meckelian (m.mk.) is of the average size ; the whole lower jaw is 

 rather weak and very flexible, quite unlike the upper jaw. As is shown also in the 

 half-grown specimen, the " aunulus" {(i.ty.) is perfect, and sends a small flange down 

 upon the intruding, down- turned columella (e.st.). The medio-stapedial (fig. 2, m.st.) 

 is long ; the stapes and the intermediate inter-stapedial lobe are partly ossified. 



As compared with P. ornatns this type is, as it were, the same exaggerated ; it is less 

 ossified by far, even in the adult, in its endocranium, but this is made up by the enor- 

 mous development of its investing bones. It comes nearer the skull of the Common 

 Froo- in the retention of large tracts of cartilage, but is less hke that " pattern " in 

 havino- no inter-stapedial. I find no second jireorbital besides the septo-maxillary, and 

 in this it is more normal ; the fenestras in the basal plate are quite peculiar. 



One thincT to be noticed is this, namely, that this Chanudeonoid skull has not been 

 speciahsed at the expense of any essential Bati-achian character ; the skull of the 

 Chameleon is a much greater modification of the Lacertilian type of skull, as I have 

 shown in a monograph on the cranium of that Family elsewhere (Trans. Zool. Soc, 1881). 



In the small Toads that form the Families most related to tlie typical kinds, we shall 

 find, with far less change of outer form, skulls that are much fuller of exceptional 

 characters than that of this species, whose abnormality lies mainly in outward form, 

 the deeper characters being on the whole true to the " norma." 



In the next FamQy of Toads, " Rhinodermatidse," the parotoids are absent, and the 

 ear is less perfect than in the " Bufonidse." 



Second Family. " Rhinodermatid^." 

 First genus. Rhinoderma. 

 G4. Rhinoderma Darwinii — Adult male; 1 inch long. Chili. 



The skull of this species (Plate 39, figs. 1-6) is peculiarly Ranine, both m form and 

 in strength; it is sub-triangular; but the skull of newly metamorphosed Toads 

 ("Bufonidai") show this, also, more or less (figs. 7-9). 



