474 Scientific Intelligence. 



tatives of this order. Of all the larger groups of the reptiles 

 from the American Mesozoic, the Plesiosaurs have probably been 

 least satisfactorily known. This is the more remarkable as the 

 group has shown a high degree of differentiation and skeletal 

 remains can not be considered as rarities. Thirty-four species 

 and nineteen genera of Plesiosaurs are listed by the author. The 

 majority of these have been known only from small portions of 

 the skeleton and, excepting the specimens described by the author, 

 the general osteology of no single species had been satisfactorily 

 worked out. The full description and the. excellent illustrations 

 of Dolichorhy7ic/iops osborni Williston incorporated in this paper 

 furnish for the first time the materials upon which a satisfactory 

 comparative study of the American forms of this group can be 

 based. Important contributions to our knowledge of the general 

 structure of the Plesiosaurs are made by the author in his inter- 

 pretation of the structure of the frontal, occipital and palatine 

 regions. In Dolichorhynchops^ the elements which represent 

 what have been considered as tiie frontals appear to be parietals 

 reaching forward to the premaxillaries and separating the true 

 frontals. The supraoccipital region in this form consists of two 

 distinct and considerably separated elements. In Jirachauchenius 

 the palatines and pterygoids are broadly contiguous along the 

 median line and the openings far back between the pterygoids 

 are thought to represent the internal nares. An important addi- 

 tion to the types of Plesiosaurs already known is made in the 

 description of Brachauchenius lucasi Williston, based upon a 

 large-headed, short-necked species from the Benton Cretaceous of 

 Ottawa County, Kansas. This genus shows single-headed cervi- 

 cal ribs and has the peculiar characters of the palate mentioned 

 above. The addition of this very distinct type to the numerous 

 genera already known serves to emphasize the statement that the 

 Plesiosaurs have shown a remarkable degree of differentiation in 

 this country. 



Professor Williston has already given us a most valuable mon- 

 ographic study on one of the groups of American marine rep- 

 tiles, viz., the Mosasaurs, and we shall look forward with much 

 interest to the appearance of his completed work on the order 

 which is now engaging his attention. j. c. m. 



5. Spodumene from Pala, California. — The beautiful ame- 

 thystine spodumene from Pala, San Diego, Cal., which was 

 described by G. F. Kunz in the September number (p. 264) and 

 named Kunzite by Baskerville (see Science, Aug. 12, and this 

 Journal, p. 335), is also the subject of a descriptive article by 

 W. T. ScHALLEB (Univ. California, Bull. Geol., iii, 265, Sept., 

 1903). The crystals are simple and show the forms in the pris- 

 matic zone, a (100), J (010), ^(320), m (110), ?z (130), ^(350). 

 The peculiar etching figures are discussed and figured in detail 

 and approximate symbols assigned to them. The following 

 results are given as the average of several analyses : 



