VI 



YORKSHIRE TYPE AMMONITES-II May 



t ^oiif ;*c nf All the Soecies By Captain Thomas Brown, M.P.S., Member 

 S^f^!^^^ ^^ Society Member of the 

 Vrnedan Natural History Society; Corresponding Member of the 

 Br th Archaeological Association ; Local Secretary of the Syno- 

 Sptian Society! Honorary Secretary of the Manchester Geological 

 Sodety ' Member of the Manchester Natural History Society, and Curator 

 onls Museum. London : Smith, Elder, and Co. And Maclachlan and 

 Stewart, Edinburgh, mdcccxlix. . 



This work was published in parts in the years 1837 to 1849 (C. Davies 

 Sherborn Proc. Malacol. Soc, VI, 1905 358). It contains new species of 

 Ammonites, namely A. cornuoides, A. minimus, and in the Appendix, A. 

 allasii A. calcar, A. cookii, A. dissimilis* A. rotifer* A. gamma : some, 

 perhaps all, of these are from Yorkshire, and those starred have been 

 found in the Manchester Museum. Search for others is requested. 



This work, if referred to, will be cited as " Brown, 1837, or 1849." 



The second is a small but important paper, with the following title :— 

 " 2. On the Kelloway Rock of the Yorkshire Coast. By John Leckenby, 

 Esq. (Communicated by John Morris, F.G.S.)— Quarterly Journal of the 

 Geological Society of London, Vol. XV, 1859, pp. 4-15, Plates i-m. This 

 paper was read on March 24, 1858, and published Feb. I, 1859 (date on 

 cover). It contains about 20 new species of Ammonites, of which many 

 are unfigured, and it supplements the works of Young & Bird, and of 

 Phillips. 



The paper will be cited a? " Leckenby, 1859." 



Terminology 



Biogenetic Terms. (See Vol. 1, p. vii). 



Homceomorphy. The following methods by which it is produced 

 may be termed 



Subparallel along similar lines, 



Cyclical turning round to go back, 



Transversal paths' of development crossing. 1 



Subparallel homceomorphy denotes the result produced by similar 

 changes in fairly similar genetic stocks — for instance, costate serpenticones 

 producing smooth sphaerocones. Examples : Cadoceras, Quenstedtoceras, 

 Cardioceras. And the catagenetic broad - whorled Hildoceratids, 

 Witchellia, etc., are examples in another direction. 



Cyclical homceomorphy denotes the result produced by species in 

 catagenesis losing their phylephebic characters, and becoming similar 

 to anagenetic species — a post-tuberculate costate species being like 

 a pre-tuberculate costate. Example : Beaniceras luridum to Mgoceras 

 capricornum. See No. 73. 



Transversal homceomorphy denotes the crossing of stocks in the 

 courses of their development. A thin stock is becoming thicker 



» See Abstracts Proc. Geol Soc. No. 938, 1913, p. 72 



