60 MR. W. K. PARKER OX THE STRUCTURE AND 



d. Ethiopian species. 

 14. Rana. ? sp. — Adult female, 1 inch long. Lagos, W. Africa.* 



The largest of the specimens examined by me was one inch long, and was a female 

 with developed ovaries. Dr. Gunther was doubtful as to the exact species of Rana 

 to which it belonged ; it was possibly immature, but evidently belonged to a small 

 and very slender kind, with proportionally extremely long hind legs : its tongue was 

 deeply bilobate, and one lobe was much shorter than the other in this specimen. t 



My dissections show this kind to have a skull closely corresponding to that of a 

 Common Frog of the first summer, or about four months after metamorphosis ; it is 

 instructive any way, whether it be yonng or arrested, for it shows how close this 

 Ethiopian species comes to our native kind, in all essentials of cranial structure. 

 That it was a mature individual I have no doubt, and it came in the same bottle 

 with adult specimens of a species of Rappia, the largest of which was only five-sixths 

 of an inch long. The general form of the skull (Plate 13, figs. 7, 8) is half a long 

 ellipse ; and tlie length is equal to the greatest breadth — a proportion which gives 

 a rather long skull for a Batrachian. 



The occipital condyles (Plate 13, figs. 7, 8, oc.c.) project very little, are not so 

 wide apart as in some small species {e.g., Rana pygmcea, Plate 5, figs. 11, 12), and the 

 emargination of the basal plate between them is slight ; the roof also (fig. 7) is not 

 cut away much above. 



The auditory capsules project moderately in front, but they have an airested, 

 smooth appearance ; their inferior surface is nearly as great as the superior ; the roof 

 of cartilage is complete up to the post-orbital region, so that there are no lesser 

 fontanelles behind the main space (fo.). The optic fenestra (II.) is small, and veiy 

 near the foramen ovale (V.). The ex-occipitals and prootics [e.o., pr.o.) are but little 

 advanced ; the former leave a wide basioccipital, and a still wider superoccipital, 

 tract soft ; the former ride over the anterior ampulla {a.s.c.) above, and are seen 

 outside the foramen ovale (V.) I^elow. The intei'orbital region of the cranial " barge " 

 is widish, and lessens very gently up to the antorbital region ; there is no ossification 

 there ; and if this be, what I am satisfied it is, namely, a mature specimen, here is an 

 instance of the entire absence of the " girdle -bone." I shall soon corroborate this 

 view by showing that another small kind of Frog is equally devoid of this bony tract. 



The ethmo-nasal region is nearly as wide as the occipito-auditory ; the roof and floor 

 {ff.ii., s.n.l.) are broad, and nearly equal. The angles of the latter, and the pro-rhinals 



* Collected by R. W. Walkek, E.sq. ; spouimens of the large 7^ BibrcDiii and li. Gniiji, brought me 

 from S. Africa by the Rev. Ambrose Wilson, came too late for this memoir. 



f This, according to Dr. Gunthee, is artificial, and due to contraction by the alcohol. Thi.'s was, 

 however, supposed by Hallowell to entitle it to a distinct generic name, viz.: Heleroglossa (see Hai.lo- 

 WELi,, Proc. A. Philad., 1857, p. 64; and Gunthek, " Batrachia Salientia," p. 26). The latter author 

 assures mc that this is a nciriiKil species of Runa. 



