DEVELOPMENT OP THE SKULL IN THE BATRACHIA. 187 



bossed, and sub-oval, with an oblique antero-siiperior emargination. The columella 

 is pistol shaped, large proximally, and small distally. The medio-stapedial (m.st.) is 

 notched above, and carries a huge unossified inter-stapedial lohe {i.st'.), not separate ; 

 the extra-stapedial (e.st.) is tongue-shaped, with a side wing which ends abrujttly 

 without an ascending process. 



The stylo-hyal {st.h.) is confluent above, and passes into a band (fig. 4, chy.) which 

 widens gently and passes back (h.hy.) into the basal plate without a lobe. The great 

 front notch is a wide semi-circular space ; the basal plate (h.h.br.) is one-third larger 

 fore and aft than in most of the Hyke ; the front lobes are small, and the hind lobes 

 sharp ; the thyro-hyals (t.hy.) are long, gently divergent, and dilated behind. The 

 mandible (fig. 3) is normal, the mento-Meckelian {m.mk.) moderate, the dentary (cZ.) 

 large, the coronoid process of the articulare {cir.) small, and the condyle (ar.c.) solid, 

 and sinuously rounded. 



The investing bones must be compared with those of Calyptocephalus and Pelobates 

 (Plates 21 and 25) ; they ai-e thick, ornately sculptiu'ed, and sub-ganoid. Where- 

 ever these bones are directly sub-cutaneous there they are elegantly honeycombed ; 

 the pits are well cleared, and the uet\vork of ridges sharp. 



The fronto-parietals (fig. \, f.p.), like the other outer bones, are wide and strong, 

 as in the species oi Bufo. Their form is many-cornered, with the antero-external and 

 postero-external margins concave, and the hind margin crenate, and notched ; together, 

 they reach, behind, over the rising parts of the auditory capsule, and each sends a 

 round process backwards which clamps the front part of the epiotic eminence (|7.s.c.). 

 Towards the middle they cover the front third of the occipital arch. Binding on the 

 anterior canal (ci.s.c.) they send a sharp jwstorbital process outwards, and then run, with 

 a concave margin, their sharp-edged superorbital plate up to the proper superorbital 

 eave {s.oh.). Their pointed diverging fore part retreats and exposes the girdle and the 

 fontanelle. There is a supraorbital fossa, beyond which the bone is strongly honey- 

 combed, and also over the temporal edge behind ; there is there, on each side, one large 

 oval fossa, more strongly marked than the rest. The nasals («.) form a pair of bony 

 wings, whose long tips bend down to lie along the top of the maxillary {mx.) ; they 

 overlap the frontals, the girdle-bone, and the ethmo-palatiues, and leave the front part 

 of the snout naked. They are only moderately wide, much angulated, sculptured, and 

 they meet to form a nasal suture, and dip to reach the " girdle." 



The premaxillaries, maxillaries, and quadrato-jugals {px., mx., q.j.) are normal in 

 form, Bufonine in strength, and have the special fretwork, outside, of this sjaecies. I 

 find no septo-maxillaries. 



The squamosals {sq.) have only a moderately broad supra-temporal part ; it binds by 

 an ii-regular edge on the parotics. The postorbital process (%. 3) is a broad, rough, 

 oblique part, whose depth is continued with little diminution to the end of the "head" 

 of the bone, w^hich thus shows an Otilophine character. The " handle" of the hammer 

 lies deep, and is therefore smooth ; it is narrower than the head, and is set on behind 



2 B 2 



