H. L. Haivhins — A New Fihilaria from Nigeria. 297 



III. — A New Species or Fibularia euom Nigeria. 



By Herbert L. Hawkins, M. Sc, F.G.S., Lecturer in Geology, University 

 College, Beading. 



(PLATE XVI.) 



AMONG a series of fossils collected in Southern Nigeria by Mr. A. E. 

 Kitson, and submitted by him to the autliorities at the British 

 Museum, are some small Echinoids. Dr. Bather has kindly allowed 

 me to examine them, and, as they appear to belong to a new species, 

 I have drawn up the following description. Eor reasons stated below 

 I ascribe the forms to the genus Fibularia, Lamk., and consider all the 

 specimens to belong to the same species. Ten individuals have been 

 used for the purposes of the description, but, to prevent possible 

 confusion, I select that numbered A as the type-specimen. 



All the examples are preserved in a pale-yellow, calcareous sandstone 

 of fine grain. Unfortunately the sand grains have often been pressed 

 into the tests, leaving a scarred surface on which it is difficult to trace 

 tubercles or sutures with any certainty. By staining some of the 

 specimens with aniline green, the pores of the ambulacra, the 

 tubercles, and to some extent the plate sutures, were rendered visible, 

 and all the details of structure given below ai'e taken from those 

 examples (Nos. A, B, E, G, H, and K). 



Fihularia nigerice^ sp. nov. 



The following are measurements (in millimetres) of the nine complete 

 specimens examined : — 



Shape. — As the above measurements show, the shape of the test 

 varies very considerably. Individuals may be either elongated or 

 approximately circular, without regard to their size, so that the 

 ambital outline does not necessarily show a change in character during 

 growth. All the specimens agree in being to some extent longer than 

 broad. The test is extremely elevated, having usually almost the 

 same height as breadth ; while, in the most elongated examples (A and 

 D), the height actually exceeds the breadth. 



The apex of the test is central, and coincides in position with the 

 madreporite. From this point the test slopes down graduallj' for 



