BRACHIOPODA. 
8. Terebratulida. 1. Terebratula. 2. Hypothyris, 3. Pen- 
tamerus. 4. Camerophoria. 5. Uncites. 
9. Spiriferida. 1. Spirifer. 2. Atrypa. 3. Martinia. 4. Stri- 
gocephalus. 
10. ThecideidcB. 1. Thecidia. 
In 1847 M. d’Orbigny {Ann. Sci. Nat. 1847 ; Paleont. Franc. 
Terr. Cret. iv. and Cours Ele'mentaire de Paleontologie, 12mo. 
p. 80, 1849) proposed the following arrangement : — 
Order I. Beachiopodes bkachides (Brachidce). 
1. Brachides propre. 
Fam. 1. LingulidtB. 1. Lingula. 2. Obolus. 
2. CalceolidcB. 1. Calceola. 
3. Productidce. 1. Productus. 2. Chonetes. 3. Leptsena. 
4. OrthisidcE. 1. Stropbomena. 2. Orthisina. 3. Orthis. 
5. RhynchonellidcB. 1. Hemithyris. 2. Rhynchonella. 3. Stri- 
gocepbalus. 4. Porambonites. 
6. Uncitidce. 1. Uncites. 2. Atrypa. 3. Pentamerus. 
2. Semibrachides. 
1. SpiriferidcB. 1. Cyrtia. 2. Spirifer. 3. Spiriferina. 4. Spi- 
rigerina. 5. Spirigera. 
2. Magasidce. 1. Magas. 2. Terebratulina. 
3. TerebratulidcB. 1. Terebratella. 2. Terebrii-ostra. 3. Fissi- 
rostra. 
4. Orbiculidce. 1. Siphon otreta. 2. Orbicella. 3. Orbicu- 
loidea. 4. Orbicula. 
6. CranidcB, 1. Crania. 
Order II. Beachiopodes cirrides {Cirrhidce). 
1. Thecidee. I. Megathiris. 2. Thecidea. 
2. CaprinidcB. I. Hippurites. 2. Caprina. 3. Caprinula. 
4. Caprinella. 
3. Radiolidee. I. Radiolites. 2. Biradiolites. 3. Caprotina. 
In 1848 Ur. Gray {Ann. §• Mag. N. H. 1848, ii. p. 435 ; 
Translated Wiegm. Arch. 1849, 98, and Loven, Arsb. 1845-1849, 
213) proposed the following arrangement : — 
Brachiopoda. — Subclass 1. Ancylopoda. 
The oral arms not extensile, or only at the tip ; on fixed 
shelly supports, or in grooves in the under or ventral valves ; the 
mantle is adherent to the shell, the substance of the shell being 
pierced with numerous minute perforations, which are pervaded 
by the processes of the mantle. 
