GENERA OF THE ARCIFEROUS ANURA. 73 



kidneys, the right originating at the anterior extremity of the latter, the left but 

 little behind it; both have their posterior apices in close contact, at the posterior 

 fourth of the length of the kidneys, which are in close connection for their posterior 

 third. In Discoglossus, the testes are oviform, well separated, and anterior, and 

 during the breeding season attain a remarkably large size. During the same 

 in Cystignathus p achy pus, they are not materially enlarged, are elongate, and 

 only in contact with kidneys for a small posterior part of their length. 



The ovaries and oviducts do not essentially vary among the Anura; when the 

 latter are fully occupied by eggs in an advanced stage they are folded, but differently 

 in the same species. The oviducts are remarkably slender in Hyla n a g u t a [Litoria 

 Giinther), and in Scytopis venulosus. The fontanelle is on each side behind the 

 partial diaphragm, at the superior anterior outer angles of the liver;, in several 

 young female specimens of Ranoidea aurea of the size of Rana si 1 vatic a, in 

 which the frontoparietal fontanelle is hot closed, the oviducts do not extend further 

 anterior than the ovaries ; in adults, with the^cranium complete, they have the usual 

 extent. In Gnathophysa ocellata* and gig as the "uterine" sacs at the exit 

 of the oviducts are of great size and at certain seasons distended with an albuminous 

 gelatine, when they present several convolutions. In spirits they occasion the 

 presence of a large convoluted coagulated mass. In one specimen on one side this 

 lay for the greater part of its length outside the abdominal muscles and above the 

 lateroventral septum. 



The tribe Arcifera was first defined and its extent and distribution indicated by 

 the author in the Natural History Review, 1865, though explained a year previously 

 at a meeting of the Zoological Society of London. The sternal feature characteriz- 

 ing it has been noticed by Steetzen, Cuvier and others in isolated cases, but its 

 general significance not perceived : Duges (Recherches, 64) attributes it to the tree- 

 toads, the toads, and the Bombinator, Alytes and Pelobates. In Stannius'f Zooto- 

 raie der Amphibien (73), it is assigned to the Aglossa .and Bufo, as distinguished 

 from Rana and Cystignathus. The characters of the last genus must have been 

 taken from the. Old World Cassina (formerly called Cystignathus), as the structure 

 in Cystignathus and its allies is that of the true Arcifera. 



These arches extend behind the so-called acromials to the extremity of the scapu- 

 la ; they have the same form and structure as during the earlier portion of the larval 

 life of the Raniforraia. In the latter, in maturing, they unite, and contract to a slen- 

 der median rod, which gives with the superior transverse portions, a T-shaped 

 element. Duges has regarded this cartilage and its halves as equivalent to the fur- 



* Rana ocellata h . R. pentadactyla of Laui\, not Ci/stignathus ocellatus of later writers. 

 t A work which should be in the hands of all students of comparative anatomy. 



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