116 MR. W. K. PARKER ON THE STRUCTURE AND 



The annulus {a-tij.) is of the typical size, broad, and its horns are not united. The 

 stapes (figs. 2 and 4, )it.) is large and oval, with its fcjre and upper edge but little 

 bevelled. The medio-stapedial [m.st.) is a strong and somewhat sigmoid rod, with 

 but little cartilage at its proximal end, where it wedges in— without any inter- 

 stapedial segment — between the stapes and the vestibule. 



Beyond the bone the cartilage soon expands suddenly into a sub-peltate extra- 

 stapedial, with a ligulate supra-stapedial confluent above [e.st., s.st.). 



The mandible (fig. 3) is normal, but veiy long and slender. 



The stylo-hyal end of the hyoid (fig. 2, st.h.) is sub-acute, and loosely attached to the 

 vestibular floor ; it does not bind strongly round the hind margin of the Eustachian 

 opening. Two-fifths of the band (fig. 3, chy.) at its lower end is reduced to a mere 

 fibrous tract, and the hypo-hyals (Ji.hy.) are quite loosed from their proper stem 

 and are confluent with the basal plate (fig. 3, b.h.br.), into which they run by a 

 Ugulate stalk. This distal part is a very large ear-shaped emarginate leaf of cartilage, 

 which, by its oblique, external angle overlaps the front lobe of the basal plate, a some- 

 what smaller, more regular leafy gi'owth, which runs almost transversely into the 

 base by a shorter stalk. Behind this, on each side, there is the normal finger-shaped 

 hinder lobe, a much smaller outgrowth of cartilage. At its root the fore end of the 

 phalangiform thyro-hyal bone {t.hy.) is set into the cartilage ; this is terminated by 

 an unossified lobe ; and the right thyro-hyal is considerably larger than the left. To 

 the lower face of the proximal part of the right bone there is a curious splint applied : 

 it is V-shaped, with all its points sharp ; the short stem behind, and the forks, which 

 are crooked, run, the right forwards and outwards, and the left obliquely outwards in 

 the other direction, under the x'oot of the left thyro-hyal. 



This, which exists- as a splint, I take to be an abortive attempt to pi-oduce an 

 ectosteal basi-branchial bone ; it will soon be described again in Alytes, and I shall 

 have to refer to it when describing a more normal (*' endosteal ") basi-branchial in 

 Bomhinator, Diplopehna, Callula, Engystoma, Rappia, and Pelodryas* 



The fronto-parietals {f.p.) are similar to what we find in many sub-typical Anura, 

 they are wedge-shaped shells of bone, with sharp fore and dilated hind ends. By 

 these bones the great oblong fontanelle is reduced to an hourglass-shaped space, only 

 half as large. The rest of the investing bones are normal ; the nasals come within a 

 moderate distance of each other, and are not very broad. With the upper labials — 

 which are normal — there is, I beheve, a small seed-shaped septo-maxillary. The pre- 

 maxillaries {px-) are widely transverse; the maxillaries i^mx.) thin and shell-like 

 in front, and sharply styloid behind; and the styloid quadrato-jugal {q.j.) is not 

 evidently grafted on to the quadrate. 



The squamosals {sq.) are shght but normal ; they fail to cover the short unossified 

 " tegmen tympani " {t.ly.). The parasphenoid (fig. 2, jm-S.) is normal, and large in 



* This is one among many instances in wliich the metamorphosis to which these icJdhyic types have 

 been subjected has only partially obliterated the form and structure of the Fish. 



