46 FORAMINIFERA OF THE CRAG. 



part of L. distoma-poUta, P. and J., from Australia ; the fourth {AmpJiorinn disforfa) 

 is unsymnietrical, and altogether analogous to those found in the Crag. 



We choose the term " gracillima^' as having been applied to the most typical form. 

 Seguenza's Amphorina glohosa. Am. tenuicalcar. Am. olivceformis, and Am. elongata (figs. 

 31 — 34), are apiculate individuals standing between Lagena gracillima and L. IcBvis. 



Lagena graciUima (under cue modification or another) occurs on the Norwegian coast 

 and in the Red Sea, on the beach near Melbourne, at Swan River, and on the Australian 

 Coral-reefs. One or two specimens are also reported from the Durham coast. 



In the Crag it has hitherto been found only in the Sutton beds. It is not uncommon 

 in the Tertiary marl of Sicily, examined by Prof. Seguenza. 



Genus — Nodosarina, Parker and Jones. 

 Nautilus, Orthoceras (parte), Orthocera, Nodosaria, Ellipsoidina (?), Glan- 



DULINA, MUCRONINA, LiNGULINA, FiSSUKINA, AmPHIMORPHINA, FrONDICULAKI A, 



Flabellina, Dentalina, Dentalinopsis, Vaginulina, Rimulina, Margi- 



NDLINA, PSECADIUM, LiNGULINOPSIS, HeMICRISTELLARIA, HeMIROBULIN A, 



Saracenaria, Cristellaria, Robulina, Planularia, &c., Auctorum.^ 



General characters. — Shell hyaline, tubuliferous, either straight, arcuate, or disco- 

 spiral ; composed of several segments, arranged in one series. Pseudopodial orifice 

 terminal and single, either central or excentric. Surface smooth, or ornamented with 

 straight, raised, parallel lines, either continuous or interrupted, sometimes reduced to 

 spines or granules, sometimes replaced by one or more keels. 



Nodosarina {Marginidina) raphanus is the central form of a large series of Foramiiii- 

 fera, whose constant variation in respect to degree of curvature, excentricity of aperture, 

 with greater or less flatness or compression, has given rise to the most unphilosophical 

 splitting up of what is practically a single species into an almost infinite number of 

 pseudo-specific forms. The so-called genera and subgenera Glandulina, Nodosaria, 

 Lingulina, FrondicuJaria, Flabellina, Rimulina, Dentalina, Vaginulina, Marginidina, 

 Planularia., Cristellaria, &c., have in this way all been constituted on characters of scarcely 

 varietal significance. With some exceptions, however, they have a certain value of con- 

 venience, which induces us, as in other cases, to admit them as representing divisions 

 or groups in an otherwise unwieldy genus, which have certain peculiarities in common, 

 though it would not be difficult to find a series of specimens which should exhibit every 

 variation, from the straightest and most elongated Nodosaria to the most lenticular and 

 carinate Cristellaria. We shall speak of these groups as subgenera, for want of a better title. 



' Ebrenberg applied the term "■ Nodosarina" (Berlin Acad. Transact, for 1838) to a correspondino- 

 group of Foraminifera, as a Family of the rolyllialamian Order of his " Bryozoa." 



