40-i Scientific Intelligence. 



Ichthyosauria of America. Notes by Marsh and Knight have 

 acquainted us with the essential characters of the paddles, but 

 little information concerning the remainder of the skeleton has 

 been published, and investigators working on related groups have 

 had no satisfactory basis for comparison with these important 

 forms. The specimens studied by Mr. Gilmore include practi- 

 cally all of the known Baptanodon material. The figures pre- 

 sented represent the complete structure of the skull in all its 

 aspects, the pectoral girdle, the anterior limb, and the anterior 

 portion of the vertebral column. The posterior limb is not cer- 

 tainly known. 



The characters of the dentition of Baptanodon, for the origi- 

 nal discovery of which we are indebted to Mr. Gilmore, have 

 been summed up in the statement that : " Baptanodon was well 

 provided with comparatively small, somewhat slender but func- 

 tional teeth that extended along the full length of the jaw ; the 

 most anterior ones being much reduced." In addition to the 

 characters of the dentition, Mr. Gilmore notes specializations in 

 the reduction of the cervical intercentra to a simple free element 

 in B. marshi, the median fusion of the clavicles, and the pres- 

 ence of a sixth digit in the anterior limb. 



In the comparison of Baptanodon with the European Opthal- 

 mosaurus, the two are shown to be remarkably similar. Dis- 

 tinguishing characters are found in the presence in Baptanodon 

 of a sixth digit in the anterior limb, the uniform biconcave cup- 

 ping of the anterior cervical centra, and the fusion of the clavi- 

 cles. The two types are, however, very close together, as simi- 

 lar as one could reasonably expect to find species so widely sepa- 

 rated geographically. 



In the light of what is actually known, the relation of Bap- 

 tanodon to the later Triassic forms of America seems still far 

 from close. Shastasaurus, the youngest known Triassic genus, 

 is at least in limb structure highly specialized along a line almost 

 diametrically opposite that taken by Baptanodon.. Unless a 

 closer connection with the late Triassic forms of this continent 

 can be discovered, we must continue to look upon Baptanodon 

 as probably a Jurassic immigrant from the old world. The close 

 relationship to the European Opthalmosaurns is additional evi- 

 dence in favor of the suggestion that Baptanodon was a Jurassic 

 importation. In this connection it is interesting to note that 

 Frass* has recently described a vertebra which he believes to 

 represent the genus Opthalmosaurns, from the Jurassic of North- 

 east Greenland. john c. merriam. 



3. Cambrian Faunas of India ; by Charles D. Walcott. 

 Proc. U. S. National Museum, xxxix, 1905, pp. 1-106. — This 

 paper is the result of a preliminary study of the Cambrian mate- 

 rial collected by Mr. Blackwelder, as a member of the Carnegie 

 Institution of Washington Expedition to China, under the le'ader- 

 ship of Mr. Bailey Willis. Previous to this expedition, Kayser, 



* E. Frass, Meddelelser om Gronland, xxix, p. 283. 



