278 



SUPPLEMEISTT TO THE EXTINCT BATRA(;H1A, J]TC. 



Protonopsis. It differs from both these genera in the absence of teeth from this bone 

 as well as its apparently small development. This may indicate that the animal was 

 not fnlly grown. In the hyoid I'egion it differs from these in the apparent absence ot 

 the second axial hyal, and in points of the hsemal segments. Thns the second is con- 

 fluent either with the 1st or 2d pleural element in those genera, and the third hjemal 

 element is much reduced and does not support the fourth pleural in either. 



The present genus is tlien to be referred to the neighborhood of A-mjiMunia and 

 JProtonopsis, but as foi"ming the type of another family. The branchial apparatus is 

 more hsh-like than in either of these, in (1) the three distinct and well developed 

 haemal bi-anchihyals, (2) the four distinct pleural elements of the same ; (3) the 

 distinct ? stylohyal. 



Its weak maxillaries have a larvnl aspect, but the ossification of all the bones and 

 the small size of the pleural branchihyals as compared with the rest of the cranium, 

 render it probable that the form is no more larval than the genera to whose neighbor- 

 hood it is referred. That it passed a portion of its existence as an aquatic branchi- 

 ferous animal is no less certain. 



COCYTINUS GYRINOIDES, Cope, Sp. Nov. 



The only specimen of this batrachiaii, embraces the inferior bones of the cranium in a complete state of 

 preservation, with the nuizzle with its teeth ; also the anterior eight vertebne with their ribs. The condition of the 

 hyal elements is as follows: The haimal element of the first branchial arch is partially concealed on both sides by 

 the ceratohyal. An expanded truncate face of attachment to the axial element is visible on both sides, but the 

 body of the bone is flat, and presents the edge in the specimen. The first pleural element proceeded from just behind 

 and within its extremity ; it is longer than the other pleural elements. A slender bone is visible extending from the 

 space between the ceratohyal and mandibular angle ; it may therefore pertain to the suspensiorium of the jaw as 

 well as to that of the hyoid arch, or be squamosal as well as stylohyal. The second ha^mal bone is slender, but with 

 enlarged axial extremity ; that of the right side is not so well preserved as to be safely determined. The third htemal 

 elements are tlie smallest, and originate immediately in front of the occipital condyles and diverge outwards and 

 backwards. They are little curved, subcylindric and slightly expanded at the extremities. 



Of the pleural elements the lirst and second are little curved, the lirst is marked by a pit or foramen on the 

 under side near the distal end, which is clearly visible on both sides of the specimen. The third and fourth pleurals 

 are more curved, and the outer ends slightly expanded and directed backwards. 



The obverse of the specimen shows that the anterior axial hyal is wedge-shaped. The lateral basihyals are 

 massive. The second hiiemal brauchihyal is dilated fan-shaped distally, and supports two pleural elements. 



The muzzle projects over the lower jaw, and was rather broadly truncate. The premaxillai-y teeth arc cylin- 

 dric and six in number on each side. The maxillary bones represented by a lamina at each lateral extremity of the 

 premaxillary. The mandibular rami aie very stout, as are ulsdf the ceratohyals. The virtebraj ha\e possessed some 

 apophyses, apparently keel-like diapophyses. The ribs are slightly curved. 



Length of head and eight vertebrte, M. .0335 ; of head .0152 ; expanse of mandibular l ami .013 ; length of left 

 ceratohyal .0085. 



