284 HENRY B. BRADY. 



C'eMws— GLOBIGERINA, (V Orhigmj. 



The extent and variety of the '' Challenger'-' soundings and 

 the large area over which the tow-net was employed during 

 the expedition have furnished opportunity for a somewhat 

 comprehensive examination of the shells of Glohigerina and 

 the allied genera. It would be impossible in a mere preli- 

 minary paper like the present one to treat the subject even 

 briefly, in its numerous aspects, neither could it be done to 

 any good purpose without the assistance of a large series of 

 illustrative drawings. These will appear in due course, and 

 with them some attempt at a complete history, but in the 

 meantime there are one or two points that may be concisely 

 touched upon, such as the range of morphological variation 

 presented by the shells of the Globigerincc, and the better 

 definition of the quasi-specific forms, together with certain 

 more general questions affecting the surface-fauna of the 

 ocean so far as it consists of calcareous Rhizopoda. 



Professors W. K. Parker and T. Rupert Jones, in their 

 philosophical and valuable memoir on ' Foraminifera from 

 the North Atlantic and Arctic Oceans,'^ record the occur- 

 rence of only two species of Glohigerina (proper), the typical 

 Gl. hulloides and Gl. inflata ; and in their supplementary 

 tables recognise but two others, Gl. helicina and Gl. hirstUa. 

 The limited number may be accounted for by the researches 

 of these authors having been conducted chiefly amongst 

 the northern and relatively stunted representatives of the 

 group, and the characters assigned to the genus are, no doubt, 

 more or less affected by the same circumstance. Their 

 generic definition, which agrees in all essential points with 

 Dr. Carpenter's more extended description,^ runs as follows : 



" The shell of Glohigerina is composed of a series of 

 hyaline and perforated chambers, of a spheroidal form, 

 arranged in a spiral manner, and each opening by a large 

 aperture around the umbilicus, in such a manner that the 

 apertures of all the chambers are apparent on that aspect of 

 the shell, and form a large ' umbilical vestibule' " {],oc. cit., 

 p. 365). It will be seen as we proceed that these characters 

 only apply to one section of the genus, and that possibly not 

 the most important, and it may even be open to question 

 whether Glohigerina hulloides, the hitherto accepted type of 

 the group, is really its best representative. I propose, there- 

 fore, to enumerate the '' species" which I iiave found it 



» ' Phil. Trans.,' 1865, vol. civ. 

 ^ ' Introduction,' p. 181. 



