TABLE OF CLASSIFICATION. 
CLASS BRACHIOPODA. 
Paterina,* Beecher, 1891. 
Sub-class INABTICULATA, Huxley; LYOPOMATA, Owen. 
Order Mesocaulia, or Lingulacea, Waagen. 
Family 
Obolus, von Eichwald, 1829. 
Ungula, Pander, 1830. 
Ungulites, Bronn, 1848. 
Aulonotreta, Kutorga, 1848. 
Acritis, Volborth, 1869. 
ScHiMiDTiA, Volborth, 1869. 
Mickwitzia, Schmidt, 1888. 
Spondylobolus, McCoy, 1852. 
OBOLIDJE, King. 
Obolella, Billings, 1861. 
Discellomus, Hall, 1871. 
Elkania, Ford, 1886. 
Billingsia, Ford, 1886. 
Botsfordia, Matthew, 1893, 
Neobolus, Waagen, 1885. 
Monobolina, Salter, 1865. 
Family LINGULIDM, Gray. 
Lingula, Bruguiere, 1792. Leptobolus, Hall, 1871. 
Pharetra, Bolten, 1798. Glossina, Phillips, 1848. 
Lingularius, Dumeril, 1806. . Dignomia, Hall, 1871, 
* The genus Paterina, representing, according to our jiresent knowledge, the fundamental stock or 
i-adicle of .all the Brachiojiods, might be embraced by some of the 2U’imitive families, both of the Inarticu- 
lata and the Ai-liculata. By placing it in this arrangement, outside both the great sub-classes, it is the 
purpose to express the fact that the genus belongs as much to one as to the other, and that it is actually 
beyond the pale of both as it has not assumed the differential characters of either. 
