390 



GENERAL SUMMARY TO 



been discovered, and the same may be said with respect to several of the other genera 

 and even families. 



A recapitulation will now be given of the results obtained in connection with British 

 fossil Brachiopoda, and especially so since the commencement of the publication of this 

 Monograph in 1850. 



In 1835 I began collecting Scottish Brachiopoda, and during many subsequent 

 years devoted much time to exploring the fossiliferous rocks in different parts of Great 

 Britain as well as of the Continent of Europe. I spared no effort in making myself 

 acquainted with all the works and papers in which British and foreign Brachiopoda had 

 been described, both before and during the preparation of my Monograph for the 

 Palaeontographical Society. 



In 1843 Prof. J. Morris issued the first edition of his ' Catalogue of British Fossils.' 

 In it he mentioned 13 genera and 454 species of Brachiopoda, but of these a certain 

 number are synonyms. In the second enlarged edition of the same work, published in 

 1854, he admitted 18 genera and some C52 species, this last edition including all the 

 species I had described up to 1853. 



As my Monograph proceeded a large number of new forms were discovered, 

 described, and figured by myself and by others, so that up to the present time some 

 74 genera, 887 so-termed species, and 89 named varieties or variations in form of some 

 of the species have been described and illustrated in my work ; but there can be no 

 doubt that with time, when some of the species are better understood, a certain 

 number of them will be found to be synonyms or modifications in shape of some of the 

 others. 



No pains have been spared by myself and by those who have assisted in the assem- 

 bling of the material described in this work. My regret is that I had to deal with 

 material coming in during all the time I have been engaged on the Monograph, thus 

 obliging me to go over the same subject at different periods, and which would not have 

 been the case if all the material could have been studied previously to commencing the 

 Monograph, in which case repetitions and alterations in views would have been avoided. 



Of these 74 British genera 15 are referable to the Tretenterata, 59 to the Clistenterata. 



3. Atrypa, Dalrnan. 



4. Aulacorhynchus, Dittmar. 



5. Bifida, Davidson. 



6. Centronella, Billings. 



7. Cyrtia, Dalman. 



8. Cyrtina, Davidson. 



9. Cistella, Wood. 



10. Camarophoria, King. 



1 1 . Chonetes, Fischer. 



12. Dielasma, King. 





Tretenterata. 



10. 



Obolella, Billings. 



1. 



Acrotreta, Kutorga. 



11. 



Orbiculoidea, d 'Orb. 



2. 



Acrothele, Linnarsson. 



12. 



Paterula, Barrande. 



3. 

 4. 

 5. 



Crania, Retzius. 

 Discina, Lamarck. 

 Dinobolus, Hall. 



13. 

 14. 

 15. 



Pholidops, Hall. 

 Sipbonotreta, Kutorga. 

 Trematis, Sharpe. 



6. 



7. 

 8. 

 9. 



Kutorgina, Billings. 

 Lingula, Bruguiere. 

 Lingulella, Salter. 

 Obolus, d 'Eichwald. 



1. 

 2. 



Clistenterata. 



Argiope, Deslongchamp. 

 Atbyris, M'Coy. 



