12 
BRACHIOPODA. 
2. Ichthyosarcolites has the cavity of the large spiral or invo- 
lute fixed valve divided transversely hy a number of oblique septa ; 
the upper valve is probably like an operculum, but this genus is 
very imperfectly knovrn. 
In 1849 Dr. H. G. Bronn {Index Talesontologicus, 8vo, p. 210) 
divided the Brachiopoda thus : — • 
A. genuina. 1. Obolus. 2. Lingula. 3. Siphonotreta. 4. Te- 
rehratula. 6. Magas. 6. Thecidea. 7- Atrypa. 8. Stringo- 
cephalus. 9. Uncites. 10. Pentamerus. 11. Camerophoria. 
12. Enteletes. 13. Spirifer. 14. Trigonotreta. 16. Delthyris. 
16. Porambonites. 17. Orthis. 18. Pronites. 19. Hemipro- 
nites. 20. Orthambonites. 21. Gonambonites. 22. Chonetes. 
23. Leptsena. 24. Plectambonites. 25. Stropbonema. 26. Pro- 1 
ductus 27 . Calceola. 
B. Rudistm. 28. Orbicula. 29. Crania. 30. Polyconites. 
31. Hippurites. 32. Radiobtes. 33. Spbaerulites. 34. Diceras. 
35. Ichthyosarcolithus. 36. Caprina. 37. Requienia. 38. Ca- 1 
protina. 39. Plagioptychus. 40. Dipibdia. 41. Monopleura. ' 
In 1850 Dr. Van der Hoeven {Handbuch der Zoologie, Leipsic, , 
1850, 80. p. 692) divided the Palliobranchiata seu Brachiopoda 
thus : — 
I. Testa acardis. 1. Lingula. 2. Orbicula. 3. Crania. 
II. Testa cardine instructa. 4. Calceola. 5. Thecidea. 6. 
Terebratula. 7- Spirifer. 8. Productus. 
Subclass 1. ANCYLOPODA. 
The oral arms recurved and affixed to shelly appendages on the 
disk of the dorsal valve. Shell minutely and closely punctate. 
Aneylopoda, Gray, Ann. Sf Mag. N. H.n. 1848,436; Cat. Brit. 
Moll. B. M. ; in Wiegm. Arch. 1849, 48. and p. 7- 
Order I. ANCYLOBRACHIA. 
Oral arms affixed to calcareous lamellae, forming a loop at- 
tached to the hinge-margin of the dorsal valve, and more or less 
prominent in its cavity. 
Ancylohrachia, Gray, Ann. N. H. 2nd ser. ii. 435, 436, 1848 ; 
Cat. Bivalves B. M. ; Wiegm. Arch. 1849, 98 (see p. 8). 
Brachiopodes brachides (Brachidae) part., D’Orb., Cours Elhi. 
Paleont. 80, 1849 (see p. 7). 
