(68 HALKYARD, Fossil Foraminifera of the Blue Marl 



Common, but never found perfect, the longest fragment 

 consisting of seven segments. Perfectly straight specimens 

 are frequent, thus showing the artificial character of the sub- 

 genus Dentalina. The forms figured by Brady are by no means 

 typical, but the form figured here almost exactly resembles 

 d'Orbigny's figures. 



(A very good series exhibiting great range of variations. 

 Many of the specimens show abnormalities of growth in the 

 diminution and subsequent enlargement of succeeding cham- 

 bers.) 



145. Nodosaria (Dentalina) consobrina, var. emaciata, 



Reuss. 



Dentalina emaciata, Reuss, 1851, Zeitschr. deutsch. geol. Ges. 



vol. Ill, p. 63, pi. Ill, fig. 9. 

 Nodosaria consobrina, var. emaciata, Brady, 1884, Chall. Rep., 



p. 502, pi. LXII, figs. 25-26. 



Much less frequent than its type species and apparently 

 confined to the upper half of the Marls. One very fine, thick- 

 walled specimen measuring half-an-inch in length was found in 

 April, 1897. This specimen is armed with a stout spine at the 

 aboral end, and in consequence of the thickness of the wall the 

 sutures are quite flush with the surface of the shell, except in 

 the last two segments where they are very slightly depressed. 



(There seems little reason for perpetuating the varietal 

 name in this very variable species. It is moreover singularly 

 inappropriate, as the variety is almost always more strongly 

 -marked in its development and growth than the type.) 



146. Nodosaria longiscata, d'Orbigny. 



Nodosaria longiscata, d'Orbigny, 1846, Foram. Foss. Vienne, 

 p. 32, pi. I, figs. T0-I2. 



Common in all gatherings, but owing to its extreme fra- 

 gility occurs only in fragments. 



(Those specimens which exhibit the initial portion of the 

 shell are furnished with a very large and bulbous primordial 

 chamber, as figured by Sherborn and Chapman (S. & C. 1886, 

 etc., M.L.C. 1889, pi. XI, fig. 17.). No specimens with micro- 

 spheric primordial chambers occur, and the possibility of this 

 species being merely the megalospheric condition of some 

 other at present unidentified must not be lost sight of.) 



