G. R. Wieland — Upper Cretaceous Turtles. 183 



Akt. XXIY. — Strxicture of the Vjpjper Cretaceous Turtles of 

 New Jersey : Lytoloma •* bv G-. R. Wieland. (With Plates 

 V-VIII.) 



In 1865 Leidy described as Chelone sopita certain chelonian 

 marginals from the Upper Cretaceous or Greensand of Tinton 

 Falls, Monmouth county, and several others from Mullica Hill, 

 Gloucester county, Kew Jersey. One of these specimens, 

 including three left marginals and part of a fourth, was figured 

 as the type.f 



In 1870 Cope established his genus Lytoloma, at the same 

 time making "a not very clear reference of Leidy's Chelone 

 sopita to both Propleura and Lytoloma.% The type species 

 of the latter genus, L. angusta, as figured, is seen to consist of 

 a single marginal and fragmentary lower jaw with a remarkably 

 long symphysis. Bearing in mind, however, the closely asso- 

 ciated manner in which the numerous forms from the New 

 Jersey Greensand occur, there is at present no positive proof 

 that this marginal and lower jaw belong to the same individual 

 or even species, although both these possibilities are probable. 



The close resemblance of the lower jaw of Lytoloma to that 

 of Chelone crassicostatum (Owen, 1819)§ was noted by Cope. 

 The latter type consists of a skull and lower jaw articulated in 

 normal position, and is a rarely perfect specimen. It was more 

 completely freed from its matrix, — a hard septarian nodule 

 from the London Clay (Lower Eocene), and further illustrated 

 and described, by Lydekker, in 1889, as Lytoloma crassicos- 

 tatum.\ Its generic relationship to L. angusta of the New 

 Jersey Greensand, and to the lower jaw from the Landenien 

 (inferieur) of Erquellinnes, Belgium, first described by Dollo 

 as Pachyrynchusfi and later referred to Euclastes,** appears to 

 be unquestioned. 



* The first paper of this series, on Adocus, Osteopy'gis, and Propleura, was 

 published in this Journal. Feb., 1904. The third paper will be on Agomphus. 



f Cretaceous Eeptiles of the United States, Smithsonian Contr. to Knowl. , 

 vol. xiv, 1865, pi. xix, fig. 5. 



X Extinct Batrachia, Eeptilia and Aves of North America, 1869, pp. 140, 

 145 ; and pi. xi, figs. 1-1 b. 



§ Fossil Eeptilia of the London Clay, Part I. Chelonia, Paleontographical 

 Society, p. 27, pi. xi. 



I On a skull of the Chelonian genus Lytoloma. Proc. Zool. Soc, London, 

 1889, pis. vi, vii. 



r Les Cheloniens, Landeniens (Eocene inferieur) de la Belgique, Bull. Musee 

 Roy. d'Hist. Nat. de Belg., t. iv, No. 3, Juill, 1886. 



** With reference to the priority and synonymy of the species here discussed, 

 it is necessary to note that the skull Euclastes platyops Cope was first men- 

 tioned in 1867; hence Euclastes antedates Lytoloma two years." Moreover, 

 according to Dollo (Sur le Genre Euclastes, Ann. Soc. Geol. du Nord., t. xv, 

 p. 114, Mars, 1888) Euclastes includes Chelone Owen, 1841 ; Lytoloma Cope, 

 1871 ; Glossochelys Seeley, 1871 : Puppigerus Cope, 1871 ; Pachyrynchus 

 Dollo, 1886 ; Erquellinesia Dollo, 1887. But later Boulenger and Lydekker 

 (Geol. Mag., Dec. 3, vol. iv, p. 270, 1887), pointed out that Euclastes is pre- 

 occupied ; thus the later name Lytoloma becomes valid. 



