262 REPORT OF NATIONAL MUSEUM, 1897. 



Test dimorphous, etc. Continued. 



Early chambers rnilioline, subsequently planospiral with more than two seg- 

 ments in each convolution Genus Hauerina. 



Chambers equitaut, arranged as in Hauerina, the last convolution covering the 



previous whorls Genus Planispirina. 



Test planospiral or cyclical, sometimes cro/ier-shaped, bilaterally symmetrical: 



Subfamily PKNEROPLIDIN/K. 



Chamber one, an undivided planospiral tube Genus Cornuspira. 



Chambers numerous, undivided, planospiral or spiral at first and rectilinear or 



cyclical afterwards Genus Peneroplis. 



Chambers subdivided transversely; early segments embracing; arrangement 



wholly planospiral or partly cyclical Genus Orlriculina* 



Chambers subdivided into chamberlets ; test discoidal Genus (Mntolites. 



Test spiral, elongated in the line of the axis of convolution . . Subfamily ALVEOLINIX.K. 



Subglobular, elliptical, or fusiform Genus A Ireolina. 



Test spherical ; chambers in concentric layers Subfamily KTCRAMOSPII.KRINYE. 



Chambers very numerous, irregularly shaped Genus Keramospliwra. 



Family VI. LAGKNID^E. 



Test monothalamons Subfamily LAGENID/E. 



A single undivided chamber Genus Laijena. 



Test polythalamous, straight, arcuate or planospiral Subfamily NoDOSARiNyE. 



Monomorphous. 



Straight or curved, circular in transverse section ; aperture central : 



Genus Nodosaria. 



Straight, compressed; aperture typically a narrow fissure.. Genus Linyulina. 

 Compressed or complanate; segments V-shaped, equitant: 



Genus Frondicularia. 

 Straight or slightly curved, triangular or quadrangular in section: 



Genus Rhabdogonhim. 

 Elongate, curved, circular in section; aperture marginal: 



Genus Marginulina. 



Elongate, compressed or complanate; septation oblique; aperture marginal: 



Genus raginnlhia. 

 Vaginuline; septation very oblique; aperture a long slit down the ventral 



face of the final segment Genus Rim-uHna. 



Planospiral in part or entirely; complanate, lenticular, crozier- shaped or 



ensiform Genus CrisMlaria. 



Dimorphous. 



Early segments Cristellarian, later ones Nodosarian Genus Amphycoryne. 



Early chambers Cristellarian, later ones Linguline Genus Linguliiioptiis. 



Early chambers Cristellarian, later ones Frondicularian Genus Fldbellina. 



Early chambers Frondicularian, later ones Nodosarian : 



Genus Amphimorpliina. 



Early chambers Rhaldogonian, later ones Nodosarian Genus Dental inopsis. 



Test polythalamous; segments arranged spirally around the long axis; rarely 



biserial and alternate Subfamily POLYMORPHININ.E. 



Monomorphous. 



Segments bi- or tri-serial or irregularly spiral; aperture radiate: 



Genus Potymorplnna. 



Segments arranged spirally around the long axis of the shell (rarely bise- 

 rial); aperture simple, usually surrounded by a phialine lip : 



Genus Urigerina. 

 Dimorphous. 



Early segments PoJymorpliine, later ones Nodosarian Genus Dimorphina. 



Early segments Urigerine, later ones Nodosarian Genus Sagrina. 



