i6 2 SOME NEW BOOKS [februahy 



" Prilogk poznava'u Foraminifera iz II. Mediteranskikh slojeva u Srbiji," and 

 was published in the Ghlasa Srpske KraVevske Akademije, pt. Ivi. 1898. This 

 deals with the Mediterranean deposits near Belgrade, and figures are given of 

 some interesting Frondiculariae. Another paper is by Detlev Lienau of 

 Konigsberg, and reads " Fusulinella, ihr Schalenbau und ihre systematische 

 Stellung " (Zeitschr. Deutsch. GeuJ. Ges. 1898). Dr. Lienau comes to the 

 conclusion that Fusulinella is a true calcareous Foraminifer, and that it does 

 not belong to the Endothyridae, as stated by Neumayr and Bhumbler. An 

 elaborate paper has also recently appeared in Falaeontographica, vol. xliv., by 

 Dr. Schellwein, dealing with the Alpine Fusulina limestone. Numerous forms 

 are figured and described, falling into many new species. Eight plates 

 accompany the text, of which six represent the genera Fusulina and Schwagerina. 

 A general paper, by Charles Upton, on " Chalk under the Microscope " (Proc. 

 Cotteswold Nat. Field Club, vol. xii. pt. 3, 1898), treats of the contents of a 

 piece of upper chalk from Purley, and is accompanied by an excellent plate of 

 various forms. 



" The Lower Cretaceous Gryphaeas of the Texas Region." By R. T. HlLL 

 and T. W. VAUGHAN: {Bull. U.S. Geol. Surv., No. 151, 8vo. 1898). 

 Pp. 66, 35 pis. 



This paper treats of the species, stratigraphical occurrence, and relationships 

 of one particular group out of the many kinds of fossil oysters found in the 

 lower cretaceous formations of Texas. The group includes those forms which 

 have been referred to Gryphaea pitcheri, Morton, and is of great importance 

 owing to the assistance which a knowledge of the forms composing it renders in 

 determining the true horizon of certain beds in geological sections. 



Unfortunately inadequate descriptions based upon imperfect specimens, the 

 true horizons of which had not been recorded, coupled with the loss for a long 

 period of the type specimen of G. pitcheri, Morton, resulted in a fearful 

 confusion of nomenclature, end gave rise to much controversy both as to the 

 species and the beds in which it occurred. 



From this condition of chaos the authors of this most carefully written 

 memoir have extricated the subject. They show that under Gryphaea pitcheri 

 no less than eight species have been included, and amongst them the familiar 

 upper chalk G. vesicularis. Six members of the group, including two new 

 species, belong to the lower cretaceous. The type species itself proved to be 

 identical Avith G. corrugata, Say, which name consequently stands. 



All these forms are fully described and figured, their geological distribution 

 and probable phylogeny is traced, and the only point which a preliminary 

 investigation suggests as wanting is some allusion to the late Felix Bernard's 

 papers on the morphology of the hinge when dealing with the nepionic stage of 

 G. Washitaensis. This last-named species, by the bye, calls to mind the well- 

 known G. vesicidaris of the upper cretaceous, both of Europe and America, and 

 was doubtless its lineal ancestor. Many of the lower cretaceous forms here 

 figured present apparent affinities to European species, though how far, if at all, 

 the authors have studied the latter does not appear. 



Anyhow much more work remains to be done on this difficult group of 

 Ostreidae before satisfactory conclusions can be reached concerning them. To 

 begin with, as the authors point out, "nearly all of the species of fossil oysters 

 have been founded upon adult forms, without knowledge of the life-history of 

 the individual. ... It is regrettable that full suites of specimens represent- 

 ing ail the species hitherto described have not been studied." In contra- 

 distinction to accepted authorities the observations of the writers of this 

 monograph lead to the conclusion " that certain forms of the Ostreidae possess 

 very distinct specific characters, have definite geologic horizons, and are (BV) 2 

 of the greatest value in stratigraphic work." 



