Carboniferous Foraminifera. By Bev. W. Hoiuchin. 535 



Family ASTROEHIZID^. 



Sub-family Rhabdammininse. 



Genus Hypeeammina, Brady. 



Eyperammina dongata, var. clavafula, nov. Plate VIII. figs. 1, 2. 



Test free, clavate in form ; primordial end inflated, rounded and 

 closed; tubular extension straight or only slightly curved, of uniform 

 diameter throughout, and short ; sometimes marked externally by 

 slightly depressed transverse lines. Texture finely arenaceous. Walls 

 thin, smooth on both exterior and interior surfaces. Aperture, the 

 open end of tubular extension. Short diameter of tube 1/130 in. 

 Length 1/30 in. 



The discovery of Hy^erammina in the Jurassic rocks of Switzer- 

 land, by Dr. Haeusler, and, almost concurrently, that of a vermiculate 

 fossil in the Silurian of Scotland (Girvanella) by Messrs. Nicholson 

 and Etheridge, which Mr. H. B. Brady thinks more than probable 

 may belong to the same genus, indicate a high probability that some 

 representatives of this very simple form might occur in the rich 

 microzoic beds of the Carboniferous Limestone. The organism now 

 described seems, in all respects, very characteristic, and comes so near 

 the smooth examples of H. elongafa, Br., that it can hardly be specifi- 

 cally distinguished from that form. It differs, however, in its minute 

 dimensions, the proportionately larger size of its primordial chamber, 

 and its shorter contour. With regard to the last mentioned feature it 

 is just possible that the Carboniferous examples fail to show the entire 

 length of the tube. Its minute size and delicate proportions render it 

 very liable to breakage in the mechanical operations of cleaning the 

 material ; but, on the other hand, I have not detected a single frag- 

 ment in the material searched that would be recognized as a fractured 

 portion of the organism. 



Distribution. — It was noted in seven samples of material, embracing 

 the Great Limestone and the " D," " H," " I," and " J " Limestones 

 of the Cowburn and Tipalt districts. It is more or less scarce 

 except in the overlying shale of the Great Limestone at Clowes Gill. 

 It maintains a remarkable uniformity of character throughout the 

 geological section, and cannot well be mistaken for any other form. 



Hyperammina vagans, Brady. Plate VIII. fig. 3. 



An adherent vermiform test of arenaceous texture ; consisting of 

 a primordial chamber (not clearly defined in the Carboniferous speci- 

 mens) and a tubular extension, the latter disposed either in more or 

 less closely set parallel lines or growing wildly and irregularly; 

 always either attached to the surface of some foreign body or forming 

 of itself acervuline masses, the diameter of the tube being about 

 1/800 in. 



It has not been an easy matter to assign a place to this minute 

 and very irregular organism. It occurs in confused masses, and it is 



2 p 2 



