NODOSARIN^. 67 



acutely oval in cross section, we might regard it as a Marf/iiiulina, such as M. Wehhiana, 

 D'Orb./ and M. obliqua, Reuss;" and, indeed, it has ahnost as much right to be in that 

 group of the NodosarincB as among the Vaginidince. 



Vaginulina linearis, Montagu. PL I, figs. 10 — 12. 



(For synonyms, see above, p. 66.) 



Characters. — Shell straight or bent, more or less compressed ; chambers compactly 

 set on, more or less oval in section ; ornamented in a variable degree with delicate 

 parallel riblets, mostly oblique to a.\is of the shell ; aperture excentric. Length 

 jth inch. 



Whether in the fine specimens from the Crag of Sutton (collected by Mr. S. V. 

 Wood) we have large Denfniince obliqucsfriafce, imperfectly ornamented, or Vacjinulince 

 liiieares, more Nodosarian in their make than usual, it is difficult to say. We adopt the 

 latter supposition. In many instances Vaginulina linearis loses its compressed shape, and 

 takes on more inflated chambers in its further growth, becoming Dentaline ; and such 

 seems to have been the habit of the Sutton specimens. After all, it is clear that neither 

 /). obliquestriafa nor V. linearis are real species, and can be separately referred to only 

 for convenience. 



As Marginulina Wehhiana, D'Orb., and J/, ohliqua, Reuss, ai'e almost indistinguishable 

 from Vaginulina lavigata, so J/, vaginella and 31. semicostafa, Reuss,' are Marginuline 

 conditions of V. linearis ; and V. recta, Karrer,* may be said to be the Marginuline form 

 of V. Icgumen proper. 



The elegant Foraminifer illustrated by pi. 5, fig. 2, ' Sitzung. Akad. Wiss., Matli.- 

 Nat. CI.,' vol. 1, part i, 1864, and described at p. 26, op. cit., by Professor Reuss, as a 

 variety of Flahellina ensiformis, Miinst. and Roem., represents the fully costate condition 

 of Vaginulina legumen, the common specimens of var. linearis being only partially covered 

 with riblets. How this Vaginulina passes into Flahellina may be seen by Reuss's figs. 

 23 and 24, pi. 2, 'Sitzung. Akad. Wiss.,' vol. xviii, 1855; whilst Cristellaria gladius, 

 Phil., fig. 31, of the same plate, shows Vaginulina legumen becoming a Cristellaria. In 

 fact, links between all the Nodosarinte may readily be found. 



As for V. linearis, this form of Vaginulina only differs from the sub-typical V. legumen 

 in costation of the surface of the shell, a character of extreme variability. Many speci- 

 mens only show these markings on the first two or three chambers, whilst in others they 

 are apparent over the greater portion, and in some cases over the whole length of the 



' Toram. Canaries,' 1839, p. 124, No. 4, figs. 7— 1 1 ; and 'Foram. Amer. Merid.,' p.24, p]..'j,figs. 17, 18. 



2 'Denks. Aicad. Wien.,' vol. vii, 1854, p. 69, pi. 25, fig. 9. 



3 'Zeitsch. Deutsch. Geol. Gesell.,' vol. iii, 1851, p. 152, pi. 8, figs. 2, 3. 

 ■• ' Novara-E.Kped.,' Abth. "Palaeont.," p. 74, pi. 16, fig. 2. 



