KONGL. SV. VET. AKADEMIENS HANDLINGAK. BAND. 19. N:O 4. 137 



It has been repeatedly noticed and stated, that the mode of life, in a free or at- 

 tached state, amongst this class does not afford sufficient characteristics even for spe- 

 cific, much less for generic, distinction; and no greater importance seems to bo 

 attributable to the feature of the chambers being subdivided or not. 



Our form commences its early growth with a thin, slender, somewhat angular, 

 half transparent, horny nodosarina-stage of a few produced chambers, the apex of 

 which always seems to be broken off. From this condition in connection with rare 

 instances of very young -- twocharabered specimens being attached endwise to shells 

 of larger rhizopodes its ordinary mode of life - - at least in its youth - - may be 

 inferred. 



Its young state ressembles very much Reophax spiculifera BRADY. The increase 

 in size of the consecutive chambers are somewhat rapid ; its agglutinating power is very 

 strong, large pieces of broken shells and some sponge-needles, but no grains of sand, 

 being used for the fabric. The aperture is usually reniform, a feature on which 

 the genus Hippocrepina DAWS, et PARK, has been founded. It is one of the most 

 abundant rhizopodes chiefly on the chalk-bottom. 



Figg. 406 407: Two specimens of Lit. scorpiurus with part of their slender 

 early stage. 



Fig. 408: the apertural end. 



Fig. 409: Longitudinal section through the medial plane. 



Syii. Beophax scorpiurus MONTF., 1808, Conchyliol. syst. 1, Genre 83, p. 330. 



Dentalina Scorpionus D'ORB., 1826, Tabl. meth., Ann. Sc. Nat. 7, p. 255, N:o 40. 

 PMargin. hirsuta D'ORB., ibid. p. 259, N:o 5. 



Lituola scorpiurus BRADY, 1864, Rhizop. Shetl.; Trans. Lin. Soc. 24, p. 467, t. 48, fig. 5. 



nautiloidea var. scorpiurus PARK, et JONES, 1865, North. Atl. and Arct. Oc.; Phil. Transact. 



155. 1, p. 407, t. 15, fig. 48. 

 scorpiurus var. DAWS., 1870, For. Gulf and lliv. St. Laur.; A. M. N. Hist. (4) 7, (1871) 



p. 86, fig. 4 (fr. Canadian Naturalist 1870). 

 Soldanii CARPENT., 1862, Introduct. t. 6, fig. 43. 



Proteonina fusiformis, pseudospiralis WILLIAMS., 1858, Brit. rec. For. p. 12, figg. 1 3. 

 Rheophax fusiformis BRADY, 1882, Ret. Rhizopod., Osterr. Ungar. Exped. Wien. Ak. Dkschr. 43. 



2, p. 99. 



Lituolina scorpiurus var. ammophila n. 



Tab. XII, figg. 410414. 



The shell of Lituolina scorpiurus when solely depending on siliceous sand for its 

 construction becomes sometimes very much enlarged, with immense, thick walls. Such 

 is the case with our form, which is built of loosely coherent grains of sand and 

 sponge-needles. This deficiency in the coherence of the structure, particularly in aged 

 specimens, is seldom met with in this class and indicates a lack of cementing secretion 



1 8 



K. Sv. Vut. Akad. Handl. Bd. 19. N:o 4. 



