FAMILY 26. PENEROPLIDAE 217 



' Subfamily 1. Spirolininae 



Test close coiled in the young, often becoming uncoiled in 

 the adult. 



Genus PENEROPLIS Montfort, 1808 

 Plate 31, figure 1 



Genoholotype, PeneropUs lanatus Monttovt:= Nautilus planatus Fichtel and 



Moll 



Peyieroplis Montfort, Conch. Syst., vol. 1, 1808, p. 259. 

 Coscinospira Ehrenberg, Abhandl. k. Akad. Wiss. Berlin, 1838, p. 131 

 (genotype, by designation, Coscinospira hemprichii Ehrenberg). 



Test free, planispiral, close coiled in the young, usually in- 

 volute, in the adult becoming variously shaped, close coiled, 

 flaring, annular or commencing to uncoil; chambers undivided; 

 wall calcareous, imperforate except in the proloculum and some- 

 times the following chamber; aperture simple at -the base of 

 the apertural face, or long and slit-like, occasionally divided. 



Cretaceous (?) Tertiary and Recent. 



Genus DENDRITINA d'Orbigny, 1826 

 Plate 31, figure 2 



Genotype, by designation, Detidritina arbuscula d'Orbigny 



Dendritina d'Orbigny, Ann. Sci. Nat., vol. 7, 1826, p. 285. 

 Peneroplis (part) of authors. 



Test similar to Penero'plis, the test usually thick and showing 

 a tendency to uncoil; aperture dendritic, in the apertural face. 

 Eocene to Recent. 



Genus SPIROLINA Lamarck, 1804 



Plate 31, figures 3, 4 

 Genotype, by designation, Spirolina cylindracea Lamarck 



Spirolina Lamarck, Ann. Mus., vol. 5, 1804, p. 244. 

 Peneroplis (part) of authors. 



Test similar to Peyieroplis, thick, early chambers close coiled, 

 usually not completely involute, later ones uncoiled; aperture 

 rounded, terminal. 



Cretaceous ( ?) to Recent. 



