Carboniferous Foraminifera. By Rev. W. Eowchin. 539 



arenaceous texture of the test at once distinguishes it from the coarser 

 Placopsiline species. The radiating tubuh undoubtedly formed the 

 general apertures of the test, they sometimes bifurcate, and there is 

 commonly a thin film or weblike extension of the testaceous enyelope 

 partly covering the spaces separating the tubuli. 



Distribution. — It is rather a common form in the " D " Limestone, 

 where it is found attached to a great variety of objects, but I have not 

 found it at any other horizon in the district. 



Wehhina irregularis d'Orbigny. Plate IX. figs. 16, 17. 



There can be little doubt, I think, that figs. 16 and 17 represent 

 examples of this species. Although difiering in some respects from 

 the recent form, they carry clearly marked Trochamminina character- 

 istics. The test is typically, although not constantly, oval in shape ; 

 finely arenaceous in structure, smooth externally, and imperfect on the 

 side of attachment. The segments are arranged in a moniliform 

 order, and sometimes in several parallel and adjoining series of such an 

 order of arrangement. The features of divergence from the modern 

 examples of the species, exhibited by the Carboniferous specimens, are 

 in the direction of a greater thickness of test, the stoloniferous con- 

 nection between the chambers is often imperfectly developed, the 

 division of segments being at times marked by a simple constriction of 

 the test rather than by stoloniferous tubes ; whilst in many examples 

 there is an approach to the cylindrical form by the margin of the 

 chambers almost coalescing on their under sides when the object on 

 which they have grown has been a column of small diameter. 



These divergences may be regarded as features of minor conse- 

 quence where the general agreement to the type is so close. Average 

 size of segments, long diameter 1/75 in. ; short diameter 1/125 in. 



Distribution. — Very rare in Great Limestone of Blagill, Allendale, 

 but common in the " D " Limestone of the Cowburn and Tipalt 

 outcrops. 



Sub-family Endothyrinse. 



Genus Archil agena, no v. 

 Syn. Lagena (in part), Brady. 



Shell parasitic or free ; either monothalamous or polythalamous. 

 Chambers inflated ; ovate, subglobular, or irregular in shape. Poly- 

 thalamous examples confused in arrangement. Test thicker than in 

 the typical Lageniclse; finely perforated. Texture either entirely cal- 

 careous or with only a small proportion of included arenaceous particles. 

 Aperture at the termination of a short neck ; in parasitic examples 

 the orifice may be defective on the side of attachment, and is then a 

 semicircular, slightly produced lip. 



The genus now described may be regarded as bearing a similar 

 relation to Lagena that Nodosinella bears to Nodosaria. In both cases 

 we probably possess ancestral, generalized types, from which have 

 diverged distinct lines of modification leading up to more specialized 



