d1':v]-:lopmi<;nt of thi<: skull in the batrachia. 237 



enlarging in the cerato-hyal region {c.hy.), and then becoming narrow again, without 

 a lobe, as the retral hypo-hyal (h.Jiij.). The basal plate is very similar to that of the 

 last kind, bnt the thyro-hyals {t.h;/.) are still longer, and more divergent ; they are 

 strongly curved upwards and outwards. The investing bones, also, are very similar In 

 the two species, allowance being made for the difterence of outline of the skull. The 

 fronto-parietals {/.l^-) are better developed in the occipital and temporal regions, and 

 as in the last, the parietal territory is anchylosed, and even somewhat adherent, to the 

 bone below. They end in the frontal region so as to leave an emargination which 

 slightly exposes the fontanelle (fo.) ; the right frontal is the longest, and yet it only 

 touches the nasal of that side, the shorter left bone overlaps the nasal in front of it. 

 These latter bones (??..) are very unsynimetrical ; they are half their own width apart 

 at the nearest pomt, and leave a large narrow-waisted bony tract bare, between them. 

 Each bone has a thick rib, or boss, over its descending or facial process (figs. 6, 8, «.), 

 and the whole facial edge (fig. 8) lies well down on the top of the maxillary {mx.) ; 

 it is gently concave there, and notched further forwards for the nasal aperture (p.n.). 

 Of these convex, rounded bones, the left is one-fourth larger than the right, and is 

 altogether further back. The premaxiilaries (px.) lie completely under the cochleate 

 snout ; they form a more definite angle at this juncture than in the last kind ; the 

 nasal process is longer, and the labials (u.P.ii.P.) are larger. The maxillary (fig. 8, 

 mx.) is deeper, the short, unciform quadrate-jugal (q.j.) is a little more attached to 

 the end of the maxillary ; it is but little united with the quadrate. The squamosal 

 (sq.) is more normal, and the shaft is bent on the upper part at a right angle ; at that 

 part the temporal region (fig. 6) is a large lozenge of bone, lying over the tegmen 

 and horizontal canal ; it is three times as wide as in the last kind. The postorbital 

 process is very small. The rostral part of the parasphenoid (fig. 7, ^^a.s.) is lax'ger 

 relatively to the wide wings ; there is a definite hindei-, triangular process, and a 

 triangular apophysis looking in the other direction between the fore part of the wino-s. 

 The whole bone, instead of being nearly as long as the skull, as in DactyJethva, is only 

 two-JIfths its length. Here, the left vomer (c.) is larger than the right ; the two pro- 

 tect the widely separated inner nostrils {in.); and the nasal palate is extremely like 

 the "hard palate" of Man ; all its elements are confluent. 



70. Phrijnisciis Icevia. — Adult female; 1;:- inch long. Ecuador. 



This species, as far as my specimens show, is the largest of the three. 



This is a slightly longer skull than that of P. cruciger, the breadth and the length 

 of it being equal. On the whole, it is as asymmeti'ical as the other two ; it has a 

 broader snout, and is less ossified ; it agrees in several things with P. cruciger more 

 than with P. varius, but like the latter species it has no columella, and no "annulus ;" 

 its less intense ossification makes it a key to the difficulties in the other two. In one 

 respect it is the most generalised of all the skulls of the Phaneroglossal types 

 examined by me as yet, e.g., the jugal arch is incomplete, as in the Aglossa. 



