106 CARBONIFEROUS AND PERMIAN FORAMINIFERA. 



NODOSINELLA CONCINNA, flOV. PI. VII, figS. 11 15. 



Characters. Test sub-cylindrical or compressed, composed of few (one to three) well 

 defined, ventricose segments. Segments variable in contour, rounded ; usually com- 

 pressed laterally, perpendicularly, or obliquely. Aperture single, simple. Length -^g- inch 

 (1-0 mm.). 



This is perhaps the most striking and best differentiated species of the genus, but very 

 limited in distribution. The test consists of a series of segments, without intervening 

 septal plates, separated only by constrictions, and bearing a strong resemblance in shell- 

 structure to the compact Trochammina . A large number of the Foraminifera from the 

 Yoredale Limestones of Swaledale, in which Nodosinclla concinna most abounds, are very 

 siliceous, and the Trochammina-like appearance of the specimens extends even to those 

 in which the original test has been entirely replaced by colloid silica. 



The individuals vary a good deal in contour ; perhaps the largest number have two 

 segments, but many have three, and on the other hand some single segments occur which 

 bear no sign of fracture or incompleteness ; whether these represent different stages of 

 growth or are alike perfect organisms, it is difficult to say. 



Distribution. In England Nodosinella concinna is confined, so far as is known, to 

 the Yoredale Rocks of a very few localities. The Rev. W. How chin has met with it in 

 the Belstonburn limestone, its only recorded occurrence in Scotland. 



NODOSINELLA LINGULINOIDES, nov. PI. VII, figs. 24, 25. 



Characters. Test elongate, tapering, compressed or complanate, straight or only 

 slightly curved. Segments numerous, successively increasing in width; sutures but 

 little excavated. Surface rough and irregular. Aperture variable. Length -^ inch 

 (1'5 mm.). 



Certain large, rough, flat specimens, occurring rarely, and often imperfect in their 

 later segments, may be conveniently distinguished under the name Nodosinella 

 lingulinoides. Their exterior is rugged and irregular, and the interior of the chambers 

 more or less labyrinthic. These characters are usually sufficient for their recognition. 



A few individuals (figs. 22 and 23, for example) of smaller size and somewhat less 

 compressed laterally were at first associated with the foregoing, but their internal 

 structure seems to indicate that they belong rather to the genus Stachcia. 



