TEXTILARIA SAGITTULA. 145 



pi. ii, ' Atti Accad. Poutif. Lincei,' vol. sxxiii, 1880, p. 69, passages from 

 T. acimlata towards sagittiila are well shown. 



T. ohsoleta, Reuss, ' Bohm. Kreid.,' 1. c, fig. 79, is a rather thick form of 

 sagittula. T. Partscliii as there figured only differs by its rounded edges; figured 

 elsewhere by Czjzek (1848, ' Haiding. Abh.,' vol. ii, pi. xiii, figs. 28 — 30), it is equiva- 

 lent to gihbosa with horizontal chambers; and prselonga, ibid., is a long narrow 

 sagittula. 



Plecanium lanceolatum, Karrer, ' Sitz. Akad. Wien,' vol. Ivii, 1868, p. 129, pi. i, 

 fig. 2, is an elongate sagittula, which loses its sharp edges in the upper part, where 

 the chambers become rather thick and squarish, as in Reuss's figure of T. Partschii. 

 So also Text, luculenta, Brady, var. Galaritana, Fornasini (' Boll. Soc. Geol. 

 Ital.,' vol. vi, 1887, p. 389, pi. x, figs. 3 — Sh), begins as sagittula, and grows up 

 with thicker, more inclined, and less regular chambers. The variety has sharp 

 edges and more inclined chambers, set more loosely together than Brady's figs. 

 5 — 8, pi. xliii, p. 864, Report ' Challenger.' 



T. Baudoidnana, d'Orb., from the Chalk (' Geologist,' 1863, p. 294, pi. xv, 

 fig. 6), is symmetrical in outline and in the setting-on of its depressed or narrow 

 chambers ; it can scarcely, if at all, be distinguished from a well-grown T. sagittida. 

 D'Orbigny states that it is near to T. communis, d'Orb, 'Ann. Sci. Nat.,' vol. vii, 

 1826, p. 263, No. 27. 



Occurrence. — Textilaria sagittula is of very common occurrence in the shallow 

 waters of temperate seas, and has a very wide geographical range. Specimens 

 have been found at depths of 2675 fathoms in the North Atlantic, and at 

 1425 fathoms in the South Atlantic. Geologically also T. sagittula is of very 

 frequent occurrence. The records at present appear to be from the Neocomian 

 (Bargate Beds) of Surrey (Chapman) ; the Gault of Folkestone (Chapman) ; 

 throughout the Chalk ; Eocene (London Clay) ; Miocene of Vienna, of Muddy 

 Creek, and elsewhere ; Pliocene of Italy, Garrucha, and St. Erth ; and from 

 several Post-Tertiary deposits. In the Coralline Crag we have found it, with 

 varying frequency, in every zone examined, and it is the only species of Textilaria 

 recorded from the Red Crag:. 



1*. Textilaria sagittula, Defrance, var. jugosa (Brady). Plate V, fig. 19. 



Polymorpha sagittulse, Soldani, 1791. Testae, &c., vol. i, part 2, p. 120, pi. cxxxiii, 



fig. s. 

 Texttjlaeia sagittula, d'Orb., 1S39. Foram. Canaries, p. 138, pi. i, figs. 19 — 21. 

 — — Beeve,18^2. Conch. Syst., vol. ii, p. 292, pi. ccvii, fig. 10. 



