84 THE EXTINCT BATRACHIA, REPTILIA 



between them on the middle line another which together enclose two shallow concavities. Superciliary margins 

 raised, the cranial table quite flat. The margin of the quadratojugal bone projects strongly. The scales of the 

 limbs are all smooth, and those of the dorsal region with very low keels. The sides have four longitudinal rows of 

 ovate scales separated by scarcely defined smaller ones. The abdominal plates are longer than broad, and are in 

 twelve longitudinal rows. Dorsals in seventeen transverse series from interscapular to crural region. The lateral 

 crests of the tail are only obtuse keels ; they unite on the thirteenth annulus behind the vent inclusive. Color above 

 dark brown, almost black on the upper surfaces of the head. The tail is paler, of a light olive brown. Lower sur- 

 faces everywhere bright yellow, including the entire lower jaw and margin of the upper. Eyelids and a band through 

 ear yellow, the former with a black spot above. 



Remarks.- — This interesting addition to our knowledge of the Reptilia was made by Schulte Buckow of New 

 York, while on a visit to the interior part of the course of the Magdalena river in New Grenada. This naturalist 

 has also enriched our collections with other interesting vertebrata of that region, both living and dead. 



OSTEOLAEMUS, Cope. 



Proceed. Acad. Nat. Sci., Phila., XII, 550, 1860. Halcrosia, Gray Ann. Mag. Nat. Hist., 1862, 273. 



As this genus has been variously understood, since its first publication, I take the present opportunity of quoting 

 the original description, and adding such observations as are necessary to a full comprehension of the species 

 embraced by it. 



" Osteolamrus, Cope, was characterized as a genus of Crocodiles presenting several points of analogy to the Alli- 

 gator. The nasal bones were prolonged anteriorly, and uniting with the short spine of the intermaxillary, divided 

 the external nasal orifice, as in the genus Alligator. The eyelids were entirely osseous as in Caiman. There was no 

 transverse bony ridge between the orbits. The dermal plates upon the tail, extremities, and the thorax, were more 

 or less completely ossified ; upon the gular region the ossification was most complete, the shields having a coarse 

 natural articulation. 



"The digits of the posterior extremity were very slightly webbed. 

 " Cervical plates distinct from the dorsal. 



"Mr. Cope alluded to the remarkable extent to which ossification was carried in this genus. The cranium was 

 much more rugose and pitted than in the adult specimens of much larger species, and the crotaphite foramina were 

 roofed over by bone. The latter peculiarity was sometimes observed in the genera Jacare and Caiman. 



"The osseous gular and thoracic buckler was also similar to that exhibited by those genera, and by the 

 extinct "Crocodilus" Hastingsise Owen, the existence of which has been shown by Professor Huxley. 



" Two specimens were exhibited : one a skin brought from the Ogobai river, Western Africa, by Mr. P. B. Du 

 Chaillu ; the other, the skull of a half grown individual, obtained from the Museum of the Pennsylvania University, 

 "These Mr. Cope regarded as belonging to a species hitherto unknown, and which he proposed calling Osteolae- 

 mus tetraspes." 



Several descriptions of species of this genus have been published under different names. It is a matter of 

 question whether all do not relate to one species. A young one was described by Murray, whose muzzle was of course 

 much broader in relation to its length than in the adult. An adult was afterwards described by Lilljeborg with the 

 relatively longer muzzle. It differed from that described by Murray in having but four rows of dorsal shields, and 

 but two pairs of cervicals ; in the latter there are three pairs of cervicals and six rows of dorsals. My type specimen, 

 brought from the Ogobai by DuChaillu possesses six rows of dorsals, and only four cervicals, thus combining the 

 characters of the two. Gray, however, who has seen Murray's type, says there are but four rows of dorsal plates ; 

 in the Ogobai specimen one row has but five, and in three others the two outer are nearly united ; so I am disposed 

 to think that no great importance is to be attached to this character. Murray's specimen has the relatively enlarged 

 brain cavity of a young animal elongating the table of the cranium ; Lilljeborg' s, which is adult, maintains this 

 character more than our specimens do. Gray gives a figure of the cranium of the adult, which coincides with two 

 crania in our Museum, one of the above mentioned specimen, while both agree in the proportions of the muzzle with 

 that described by Lilljeborg. The last, however, differs from all these in having the table of the cranium but little 



