136 GOES, RETICULARIAN RHIZOPODA OF THE CARIBBEAN SEA. 



Trochammina incerta D'ORB. 



Tab. XI, figg. 404405. 



This form is one of the smoothest amongst the arenaceous group of this class, 

 being composed of the finest siliceous particles and probably a large quantity of se- 

 creted or precipitated cementing siliceous matter, the lime being quite absent; a rusty 

 colouring matter renders the shell yellowish brown. It is very regularly formed, some- 

 what biconcave. The aperture is a very narrow crescent placed on the inner part of 

 the last convolution. It is sparsedly met Avith on the chalk-bottom, attaining a dia- 

 meter of 2 to 3 m. m. 



Fig. 404: side-view of Trochammina incerta. 



Fig. 405: edge-view. 



Syn. Operculina incerta D'ORB., 1839, Cuba, p. 49, t. 6, figg. 1617. 



cretacea Rss., 1845, Bohm. Kreide 1, p. 35, t. 13, figg. 64 65 (sec. PARK, et 



JONES). 

 ? punctata Rss., 1849, Neue Foramf. osterr. tert. Becken; Wien. Ak. Dkschr. 1. 1, 



p. 370, t. 46, fig. 21. 

 Orbis iiitimus STRICKLAND, 1846, Microsc. Shells found in the Lias; Qu. Jouvn. geol. Soc. 2 



p. 30, fig. a. 



Spirillina arenacea WtLUAMs., 1858, Brit. rec. for. p. 93, fig. 203. 



Trochamnina squamata var. incerta CARP., 1860, Introduct. p. 141, 312, t. 11, fig. 2. 



incerta PARK, et JONES, 1869, The perm. Troch. pusilla etc.; A. M. N. H. (4) 4, 



p. 388, t. 13, fig. 1. 

 BRADY, 1876, Carbonif. and Perm, foramf.; Pal. Soc. 30, p. 71, t. 2, 



figg. 1014. 

 Ammodiscus Rss., 1861, Entwurf einer systematischen Zusammenstellung etc.; Wien. Ak. 



Sitz.-Ber. 44, p. 365. 



Serpula Boesleri SCHMID, 1867, Leonh. u. Bronn. Jhrb. 1867, p. 583, t. 6, figg. 46 47. 



Ammodiscus infimus BORNEM., 1874, Ueber Involutina; Zeitschr. deutsch. geol. Ges. 26, p. 725, 



t. 8, figg. 47; t. 9, fig. 8. 

 miocenicus KARR., 1877, Hochquellenwasserleitung; Osterr. geol. Reichsanst. Abh. 9, 



p. 372, t. 16, fig. 2. 



PCornuspira Hornesi KARR., 1865, Wien. Sandstein.; Wien. Ak.~Sitz.-Ber. 52, p. 495, figg. 1011. 



granulosa, infraoolithica, silicea, aspera TERQUEM. (sec. BRADY 1. cit. p. 72). 



oolithica SCHWAG., 1867 (sec. BRADY 1. cit. p. 72). 



infima BLAKE, 1876, Yorkshire Lias p. 451, t. 18, fig. 2. 



(Vide etiam BRADY, Carbonif. and Perm, foramf.; Pal. Soc. 30, p. 7172) 



Lituolina seorpiurus MTFRT. 



Tab. XI, figg. 406409. 



A great deal of confusion has been brought into the designation and definition 

 of the genus Lituolina; and of late the dissociation of its closely allied forms even 

 into new genera, based upon very trifling and inconstant characters, has scarcely con- 

 tributed to advance our knowledge as to the real relation between its different forms 



