THE BRITISH FOSSIL BRACHIOPODA. 



391 



British so-termed species may be fairly said to have been doubled in number since 

 the commencement of the publication of this Monograph. Science is continually on the 

 advance ; and I wish all I have done to be considered as more or less provisional, and as 

 an incentive to others to continue researches in the same direction, improving upon the 

 work I have sketched out ; for there remains so much still to be found out, matured, 

 and corrected, that the subject will repay any amount of labour bestowed upon it. 



Geologists have also been hard at work during the last forty or more years, and have 

 effected many very important improvements and rectifications in the stratigraphy 

 previously known. Many of these will be found embodied in Prof. Morris's valuable 



13. Dayia, Davidson. 



14. Davidsonia, Bouchard. 



15. Eichwaldia, Hall. 



16. Kaysaria, Bav. 



17. Koninckella, M. Chalmas. 



18. Glassia, Bav. 



19. Kingina, Bav. 



20. Leptoccelia, Hall. 



21. Leptsena, Balman. 

 22.? Meristella, Hall. 

 23. Magas, Sow. 



24.? Meganteris, Suess. 



25. Martinia, M'Coy. 



26. Merista, Suess. 



27. Meristina, Hall. 



28. Nucleospira, Hall. 



29. Orthis, Balman. 



30. Orthisina, d'Orb. 



31. Productus, Sow. 



32. Porambonetes, Pander. 



33. Pentamerus, Sow. 



34. Uncites, Befrance. 



35. Rensselseria, Billings. 



36. Reticularia, M'Coy. 



37. Retzia, King. 



38. Rhynchopora, King. 



39. Rhynchonella, Fischer. 



40. Stringocephalus, Befrance 



41. Spirifer, Sow. 



42. Syringothyris, Winchell. 



43. Strophomena, Rafinesque. 



45. Streptis, Bav. 



46. Stricklandinia, Billings. 



47. Skenidium, Hall. 



48. Streptorhynchus, King. 



49. Stropbalosia, King. 



50. Terebratula, Klein. 



51. Terebratulina, d'Orb. 



52. Terebratella,d'Or6. 



53. Thecidium, Befrance. 



54. Trigonosemus, Koenig. 



55. Terebrirostra, d'Orb. 



56. Triplesia, Hall. 



57. Whitfieldia, Bav. 



58. Waldheimia, King. 



59. Zellania, Moore. 



44. Spiriferina, d'Orbigny. 



In vol. v of the ' Systeme Silurien de la Boheme,' explanation of pi. 152, M. Barrande proposes a new- 

 genus Paterula for a small Biscina-sh&ped shell with a narrow flat margin. His type is the Paterula 

 bohemica, and it closely resembles another small similar-shaped or identical species (?), which I figured and 

 described at p. 210, pi. xvii, figs. 41, 42, of my ' Silurian Supplement' under the name of Biscina{?) 

 balcletchiensis, from the Llandeilo shales of Balcletchie, in Ayrshire. This small fossil occurs there as 

 well as in Bohemia in immense numbers, and I felt at the time very uncertain whether I was correct 

 while referring it to Biscina. Unfortunately M. Barrande did not describe his genus or species. 



Besides the above-named 74 genera some of our British species have been referred by both British 

 and foreign palaeontologists to other genera ; but of these the larger number are, I think, synonyms 

 — for instance, Aulacothyris, Douville, for Wald. resupinata ; Acanthothyris, d'Orb., for Rh. spinosa ; 

 Actinoconchus, M'Coy, for Actin. paradoxus ; Brachythyris, M'Coy, for Sp. duplicicosta ; Cleiothyris, 

 Phillips, for some Atrypce ; Bictyothyris, Douville, for Ter. coarctata ; Biccelosia, King, for Orthis 

 biloba ; Berbya, Waagen, for Streptor. senilis ; Eudesia, King, for Wald. cardium ; Hemithyris, d'Orb., 

 for Rhynchonella psittacea ; Lyra, Cumberland, for T. lyra ; Liothyris, Douv., for T. carnea ; Leptagonia, 

 M'Coy, for Stroph. rhomboidales ; Macandrevia, King, for Waldheimia cranium ; Monobolina, Salter, for 

 Obolus plumbeus ; Megathyris, d'Orb., for Argiope ; Orbicula for Biscina ; Platistrophia, King, for Orthis 

 biforata ; Seminula, M'Coy, for Rh. pentahedra ; Uncinulus, Bayle, for Rh. Wilsoni ; Zellaria, Bayle, 

 for Wald. cornuta, &c. 



"Were we to indulge in the system of making genera out of every trifling and unimportant difference 

 the number would become so great that it would not only confuse the subject, but render the study of the 

 Brachiopoda one of repulsive difficulty. 



