Trof. T. Ritpert Jones — On Swiss Jurassic Foraminifera. 213 



afiects the half-tum envelopment, on one, two, or three planes. 

 The Adelosina of D'Orbigny, however, is just this young state 

 of Miliola, con'stnicted in the same subdiscoidal form, and has 

 been recognized as the general type of young Miliola. The sub- 

 sequent plan of growth is so much varied (within certain limits) as 

 to give room perhaps for the somewhat convex Spiroloculine form 

 indicated by " OpMhalmidium" though not of special value. What 

 is of more importance is Dr. Kiibler's statement as to the porosity of 

 some of these individuals, such as pL 4, v., fig- 5 {Oph. superbum), 

 and pi. 2, i., fig. 7 {Oph. porosum). Although Dr. Kiibler warmly 

 and conscientiously avows his belief that these are not merely 

 punctate shells, we cannot help thinking that the microscopic ap- 

 pearances, with transmitted light, in specimens mounted with 

 turpentine or balsam, have deceived him. The larger perforations 

 noticed in the specimens appear to be accidental, and not in anywise 

 essential. 



The several Foraminifera! group& above treated of are evidently 

 members of one fauna, existing through the Jurassic period, without 

 undergoing any great modifications. Indeed the same fauna is 

 fully recognizable in the Triassic strata. The Swiss specimens 

 under notice comprise Cornuspira ; Miliola (Biloculina; Quinquelo- 

 culina, Spiroloculina) ; Trochammina ; Endothyra (?) ; Nodosarina 

 (Lagena, Nodosaria, Dentalina, Vaginulina, Marginulina, Frondi- 

 eularia, Flabellina, Cristellaria, Planularia) ; Polymorphina ;: Texti- 

 laria ; Virgulina ; Spirillina ; Planorbulina,. 



The Miliolinoe appear to be more fully represented in these Jurassic 

 beds of Switzerland than in those of other countries. The rotaline 

 Lituola ("Botalina Badensis"),. or EndotJiyra (?),of the Gxfordian of 

 Effing, is interesting (if it be sandy, as we presume), being of the 

 curious series of arenaceous Foraminifera that imitate the hyaline 

 forms, and among which the Lagenoid, Flabelliaoid, and Marginu- 

 linoid LituolcB, figured by Terquem, from the Inferior Oolite (Parkin- 

 soni-bed), are well-marked types. 



The Nodosarina are abundantly represented, mostly by very 

 simple, feeble, and variable forms, as is usual in the Triassic, 

 Ehsetic, and Jurassic strata. 



Spirillina Helvetica, from the Middle Brown Jura (Opalinus-clay 

 and Parkinsoni-clay is the oldest known of the genus. 



The Planorhulince comprise three species : 1. One near PL 

 ammonoides (" Nonionina oblonga," " iV". Birmenstorfensis," " N. 

 Badenensis"), from the Macrocephalus-bed of the Lower Callovian ; 

 the Oxfordian of Birmenstorf, the Corallian of Geissberg, and the 

 Kimmeridgian formation at Baden, Aargau : 2. PI. Siblingensis from 

 the Oxfordian Impressa-clays of Effing : and 3. PL MoescM from 

 the Astartian formation of the Kimmeridgian stage of Eo-dersdorf. 



Mr. W. K. Parker, F.E.S., has kindly aided me in forming an 

 opinion on several difficult points in the study of Dr. Kiibler's 

 descriptions and illustrations of these fossil Foraminifera of Switzer- 

 land. 



