Vol. 60.] THE DISTRICT SURROUNDING- THE DARDANELLES. 293 



in a radius of 3 mm. The filets cloisonnaires are sinuo-striate 



and delicate. The chamber-ratio is irregular : ,./ f , = ~, -. The 



VV id th 1 3 



septal angle is about 45°. The spire is irregular after the first 

 few turns, and the line of the spiral duplicates and coalesces 

 occasionally. 



This nummulite is identified as Nummulites Dufrenoyi, D'Archiac, 

 form B. 1 De la Harpe refers N. Dufrenoyi to the N. complanata 

 of Lamarck. It undoubtedly belongs to the complanata -group : but 

 it is quite sufficiently distinct, as D'Archiac has shown, and the 

 true N. complanata nowhere occurs in these rock-specimens. More- 

 over, the * companion '-form of the species diners from N. Tchiha- 

 tcheffi, D'Archiac, which is the ' companion ' of A r . complanata. 



2. (PI. XXV, fig. 4.) A moderate-sized nummulite varying in width 

 from 8 to 10 millimetres, and having a thickness of about 5 mm. 

 Megalospheric, with six turns of the spiral in a radius of 3 mm. 

 Filets cloisonnaires sinuo-striate and rather coarse. Spire 



fairly regular. The chamber-ratio is rather irregular: eig * = -, -. 



Surface non-tuberculate, but the ' pillars ' are visible as white 

 specks on a varnished surface. Septal angle = about 50°. This 

 nummulite occurs in great abundance in the main Xummulitic 

 rock at Vernitza. It agrees fairly in dimensions with N. Tcliiha- 

 tclieffi. D'Archiac, but diners considerably in the general appearance 

 of its horizontal section. It is identified as N. Dufrenoyi, D'Archiac, 

 form A. 



3. (PI. XXV, fig. 5.) A microspheric nummulite, measuring 

 about 15 mm. in width, and rather thin. Filets cloisonnaires 

 sinuo-radiate. Delicate in its characters. The dimensions are not 

 given, because very few specimens have been secured sufficiently well 

 preserved for accurate measurement, and no specimen from which 

 the thickness could be properly measured. On the other hand, a 

 varnished specimen has furnished a fairly -good photograph of the 

 spire, except the first few turns. This nummulite is provisionally 

 identified as a variety of N. distorts, Deshayes, form B. 2 



4. (PI. XXV, fig. 6.) A megalospheric nummulite, rather smaller 

 than Xo. 2, varying in width from 5 to 8 mm. and in thickness from 3 

 to 4 mm. The spire is regular at first, and gives seven or eight turns in 

 a radius of 3 mm. ; it then frequently becomes more or less irregular. 

 The filets cloisonnaires are sinuo-striate, and more delicate 



than in Xo. 2. The chamber-ratio is regular : w ", = y ; septal 



angle = about 75°. Although in external appearance this num- 

 mulite and Xo. 2 are somewhat similar, the spiral characters are 

 strikingly different. This Xo. 4 is provisionally identified as a 

 variety of JS\ clistans, Deshayes, form A. A goodly number of 



1 D'Archiac & Hairne, ' Description cles Animaux fossiles du Groupe Nurnniu- 

 litique de l'lude' 1853, p. 89 & pi. i, figs. 4a-le. 



2 Deshayes, ' Descr. Foss. rec. en Crimee, &c.' Mem. Sec. Geol. France, vol. in 

 (1838) p. 68 & pi. \, figs. 20-22 ; DArchiac & Haime, ' Descr. Anim. foss. Groupe 

 Numnmlitiuue de l'lnde ' 1853, p. 91 & pi. ii, figs. 1 a-c, 2 a, 3 a, 4 a. 5 a, & 5 b. 



