234 G. E. Girty—Triticites. 



Art. XXI. — Triticites* a New Genus of Carboniferous 

 Foraminifers ;f by George H. Girty. 



Whex. in the course of preparing a report on the Permian 

 fauna of the Guadalupe Mountains, I came to study the species 

 described by Shnmard as Fusulina elongata^ my attention 

 was engaged by a structural difference of some mark between 

 it and the form from the Coal Measures strata of the Missis- 

 sippi Valley, commonly identified as Fusulina cylindriea. I 

 was consequently led to consider the structure of typical Fusu- 

 lina, and found that the Guadalupian species, and not the 

 common Pennsylvanian one, agrees with the Russian form. 

 The discriminating character which is shown by Fischer-de- 

 "Waldheim's original figures of Fusulina, by specimens from 

 Russia, and by most figures and descriptions in manuals,§ etc., 

 resides in the partitions which separate adjacent chambers in 

 the same concentric series. 



As is well known, each chamber is formed by a narrow pro- 

 longation of the outer wall in the direction of revolution, fol- 

 lowed by a sharp deflection toward the axis to meet the 

 volution below. The partition thus formed is not, however, 

 complete, minute apertures being left along its lower margin. |j 

 Iu true Fusulina this partition wall is strongly and regularly 

 fluted in a radial direction, and the arrangement is such that 

 the concave flexures of one partition are opposite the convex 

 flexures of the next, the approaching curves coming in contact 

 more or less precisely along a line. Thus what would other- 

 wise have been a single long chamber extending unobstructed 

 from end to end, is divided into a large number of chamberlets. 

 These are usually quite regular and have the shape of prisms 

 with subrhombic section. The regular fluting of the partitions 

 is often well shown by the aperture, but no intimation of it is 

 conveyed by the straight depressed sutures which prominently 

 mark the external surface. Apparently the fluted structure is 

 not introduced until just after the wall has assumed a radial 

 direction, when it is concealed by the overlap of the succeed- 



*From triticum, a grain of wheat. 



f Published bv permission of the Director of the U. S. Geological Survey. 



i St. Louis Acad. Sci.. Trans., vol. i, 1859, p. 388. 



§ As, for instance, on p. 31 of Steinmann and Doderlein's Elemerite der 

 Palaontologie (Leipzig, 1890), on p. 104 of Zittel's Handbuch der Palaon- 

 tologie, Bd. I (Munich and Leipzig, 1876-1880), on p. 32 of Zittel's Textbook 

 of Palaeontology (London and New York, 1896), on p. 136 of Nicholson and 

 Lydekker's Manual of Palaeontology, vol. i (Edinburgh and London, 1889), 

 etc. See, also, Geology of Eussia, etc., by Murchison, de Vemeuil, and 

 Keyserling, vol. ii, 1845, pi. i, fig. le. 



|| Indicated by the frequent failure of the partition walls to extend to the 

 preceding volution. 



