470 SYSTEMATIC PALEONTOLOGY 



on the opposite side. As the size of the segments usually increases pro- 

 gressively, the outline of the shell is generally more or less triangular, 

 the apex of the triangle being formed by the first segment, and its base 

 by the last two." (Carpenter, Introduction to the Study of the Fora- 

 minifera.) The shells of this genus show great variation in struc- 

 ture, shape, and composition of the shell substance. Typical forms are 

 hyaline with large, closely set pores, but the larger varieties are often 

 composed of arenaceous grains and either have a siliceous base or cal- 

 careous matrix. The best examples come from shallow waters of tem- 

 perate and tropical seas, but the genus is very widespread and is found 

 at considerable depths. Its geological distribution is interesting since it 

 is one of the earliest types we find developed and it is known from the 

 Paleozoic deposits. 



Textularia abbreviata d'Orbigny. 

 Plate CXXXTI, Fig. 4. 



Texifdtiriii ahbreulnta d'Orbigny, 1846, Foram. Fossiles Vieune, p. 24'.i, pi. xv, figs. 



9-12 (error for 7-12). 

 Textularia abbrevialn Bagg, 1898, Bull. Anier. Pal., No. 10, p. 18. 



Description. — Test short and thick, sharply pointed at the posterior 

 «nd, rapidly enlarging above, laterally compressed, but not strongly so. 

 being broadly elliptical in outline, with narrowly rounded margins ap- 

 proaching angularity. The chambers are narrow and increase in size 

 rapidly towards the ultimate chamber; septal lines straight, apparent as 

 fine lines, not depressed; aperture a semilunar arch on interior margin 

 of final segment. 



Occurrence. — Choptank Formation. Governor Euu. 



Collection. — Marjdand Geological Survey. 



Textularia agglutinans d'Orbigny. 

 Plate CXXXII, Fig. 5. 



Textulariii xf/f/lutinans d'Orbigny, 1839, Foram. Cuba, p. 136, pi. i, tigs. 17, 18; 



32-34. 

 Textularia a(j(jlntinam Bagg, 1898, Bull. Amer. Pal., No. 10, p. 19. 



Description. — Test agglutinous, elongated, tapering but slightly; of 

 a dull gray color; laterally convex; peripheral margin lobulated, rounded ; 



