THE FORAMINIFERA OF THE ATLANTIC 

 . OCEAN. 



LITUOLIDAE. 



By Joseph Augustine Cusiimax, 



Of the Boston Sociclij of Naturnl I list on/. 



INTRODUCTION. 



This second part of the work on the AtLnntic Foraminifera deals 

 enth'elj with the Lituolidae, the family naturally following: the Astro- 

 rhizidae, which has already been taken up in Part 1 of this work. 

 The same arrangement of data is here followed. The classification 

 is that adopted in Part 1 of my work on the North Pacific Fora- 

 minifera. The distribution of various species shows perhaps more 

 clearly than in Part 1 the faunal areas developed in the western 

 Atlantic. 



SYSTEMATIC PART. 



A systematic presentation of the various groups of the families 

 follows : 



Family 3. LITUOLIDAE. 



Test consisting typically of two or more chambers connected with 

 one another, arranged in a linear, planospiral, or trochoid, coiled or 

 irregular series; wall of agglutinated material, the relative amounts of 

 cement and foreign material varying greatly; apertiu'cs usually 

 one to each chamber, but sometimes several. 



Typical tests of this family are clearly of agglutinated material 

 from which they differ from certain parallelisms in other families. 

 The cement is characteristically ferruginous, a reddish brown in 

 color, although occasionally specimens occur where the entire test 

 is whitish and in numerous species, especiall}' in fresh or alcoholic 

 specimens or sometimes in dried material, the portion of the test next 

 the aperture is often whitish. Throughout the family as hero 

 modified the test is composed of two or more chambers with a defi- 

 nite proloculum. The exception to this is the case of ver}' largo 

 megalospheric specimens of Ilorinosina glohulifera, for instance^ 

 where there is but a single chamber instead of the several chambers 

 of the typical microspheric test. 



There seems to be a definite development of complexity of struc- 

 ture from the linear series of BcopJiax and Ilormosina through the 

 close-coiled planospiral Ilaploplivagmoidcs to the uncoiled Ammo- 

 haculites in the more highly developed species of which the early 

 coiling is very much reduced. 



121802—20 1 1 



