UTUOl.A. <>:} 



b. Segments joined together in a single ro\v. Test straight and Nodosaria- 

 like, or arcuate like Lailaliita. The terminal aperture simple. 

 e, Reuss." 



Minute criticism on this scheme of classification would lie out of place for many 

 -ons ; partly in that it would occupy space that could not very well be spared for it, 

 but much more because until the full bearing of the results of recent deep-sea dredgiiigs 

 is understood, it would be futile to suggest terms for its modification or revision. The 

 vast additions to our knowledge of the arenaceous Rhizopoda which have accrued from 

 researches made within the last few years on the deep-sea bed will, it is hoped, yield the 

 basis for a more satisfactory arrangement of the entire group than has hitherto been 

 practicable. One or two points, however, require notice. Professor Reuss's group 

 "LituoliJea" must not be supposed to be coextensive with the family "Lifuolida " of 

 Messrs. Carpenter, Parker, and Jones, for in point of fact it scarcely even includes as 

 much as the generic term " LittioJa" as employed by English authors. The propriety of 

 separating the labyrinthic and nonlabyrinthic forms seems confirmed by the strikingly 

 distinct characters of the large deep-sea specimens, and this has led to the adoption of 

 Professor Reuss's generic term, Haplopliragmium, as distinct from Lituola proper, in the 

 present paper. 



If it be desirable to separate the moniliform or uniserial varieties from the helicoid 

 forms by a generic or subgeneric term, de Montfort's name Reopliax must take pre- 

 cedence of Reuss's Haplosticlir. Hut it is unnecessary to dwell on points like these. 

 Lituola (proper) is represented in the Carboniferous beds by the typical form, and by 

 a very fine large nautiloid variety, both of them very rare. 



LITUOLA NAUTILOIDEA, Lamarck, PI. VIII, fig. 7 , I. 



LITUOLITES XAVTILOIDEA, Lamarck, 1804. Ann. Mus., vol. v, p. 243, No. 1 ; vol.viii, 



pi. Ixii, fig. 12 5 1822, Anim. s. Vert., vol. vii, p. C04, 

 No. 1. 

 DIFFOKMIS, Id. Ibid., vol. v, p. 2-13, No. 2 ; vol. viii, pi. Ixii, fig. 13, a, I ; 



1822, Anim. s. Vert., vol. vii, p. 605, No. 2. 

 XAUTILOIDEA, Parkinson, 1811. Organic Remains, vol. iii, p. 101, pi. xi, 



fig. 5. 



DIFFOBMIS, Id. Ibid., p. 161, pi. xi, figs. G, 7. 

 LITTOLA XAUTILOIDES, Lamarck, 1822. Tableau Encl. Mcth., pi. cccclxv, fig. 6. 



DIFFORMIS, Id. Ibid., pi. cccexlvi, fig. 1, a, b. 



(et LITCOLITES) NAUTILOIDES, BlaintUle, 1824. Diet. Sci. Nat., vol. xxvii, 



p. 81; vol. xxxii, p. 190; Atlas Conch., pi. xx, 

 fig. 3 ; 1825, Malacologie, p. 381, pi. xi, fig. 3. 



