480 DE. W. G. EIDEWOOD Olf THE LAEVAL HTOBEANCHIAT/ 



sucker, whicli in all probability represents the persistent and 

 greatly enlarged ventral sucker which in our common frog is 

 characteristic of the very early larvae breathing by external 

 gills, enables the tadpoles to adhere to rocks and stones in the 

 mountain torrents in which they live. It gives a most singular 

 appearance to the tadpole, but appears not to a£Pect the internal 

 organs. The hyobranchial skeleton, at all events, differs from 

 that of R. temporaria only in that the internal or mesial parts 

 of the ceratohyals are more expanded, and that the hypobranchial 

 symphysis is shorter. 



jRhacopliorus differs from Hana only in the shallowness of the 

 hyoglossal sinus, and in the fact that the hyobranchial plates are 

 longer than broad, the reverse obtaining in the frog. The early 

 tadpole of Oxyglossus possesses a hyobranchial skeleton which is 

 remarkable for the relatively great size of the hyoid arch and 

 the small development of the branchial system. The width of 

 the branchial part of the skeleton is much less than that across the 

 hyoid even at this early stage (see fig. 6). Filling the hyoglossal 

 sinus and projecting some little distance in front of it, is a dense 

 fibrous mass in which the normal transverse ligament is not 

 clearly differentiated. The branchial bars are short, thin, and 

 straight, and have no spicula. The first ceratobranchial is con- 

 fluent with the hypobranchial cartilage, while the other three 

 are attached by means of a well-marked fibrous tissue. Since 

 there are no fourth spicula, the laryngeal sinus is very shallow; 

 but it probably deepens later by absorption of the hypobranchial 

 cartilage. The spaces at the side of the copula are well defined 

 and triangular in shape. The pars reunions is but feebly 

 developed, and the ceratohyals touch one another in the median 

 line. 



The specimen of Fhyllohates examined was one taken from 

 the back of the father, to whose skin the tadpoles adhere in time 

 of danger. The hyobranchial skeleton difiers from that of Bana 

 chiefly in the greater relative size of the hypobranchial plates 

 and the corresponding smallness of the copula. The symphysial 

 line disappears in the posterior third, so that the two hypo- 

 branchial plates are fused here. The first ceratobranchial is 

 confluent with the hypobranchial plate, while the other three 

 adhere by fibrous tissue, as in Mana^ Oxyglossus, ItJiacopJiorus, 

 and probably in many other genera. Spicula are present, but 

 they are proportionately shorter and more stunted than in Bana. 



