BRACHIOPODA. 



^ 1 



01 



Thomas Davidson and William King * and though fifteen years have now 

 elapsed since the date of its publication, later observations have hitherto added 

 comparatively very little to the results achieved by these eminent investigators, 

 and have taken nothing awa}- from their value. The scope of this work in- 

 cluded not only a detailed discussion of the characters and rehitions of the 

 family, involving the establishment of an elaborate anatomical nomenclature, 

 but also descriptions of all the species then known to represent the three genera, 

 Trimerella, Monomerella and Dinobolus. This nomenclature we have adopted 

 w^ithout essential modification, and its application is sufficiently exphiined by 

 the accompanying , .^^^^ 



outlines, showing , ; / % f 



the internal feat- i ^=^$^^Sl]^^^% ' ^ ■'" 



ures 01 Irimerella, ^y'^ryt''']'^' ^IW'" 



taken from the same ^ f'' ' \aYa\ v\^'^ ^""/t^r • ' W)^ "^'^'^'^"'^ 



work. We have '-jl v-' '^~'' "^^U 11" '„::."--*-^ ' • ■ 



also accorded recog- ^""i \ / | ' ^.. 



nition to the generic 

 term Rhinobolus, 



which was made a fig. is. Pedicle-vnUc of TnmereHa. Fig. 16. lirachial valve of Trimerella. 



. f_ After Davidson anO King. 



synonym lor i rim- „, rleltiilium. <>, canlinal sockcU. 



Ij, (leliidial slope. j. pl.atloini. 



WPPTI A in tlintvporV <^. dcltidial ridges. k, platform vaults. 



ERELLA in tnai worn, ,, ^,,^.j, ,j,„.,,e?s. (,' median plale. 



e, cardinal callosities. *n, median .scars, 



but we now possess /■ cardinal facet. ii, anterior scars. 



^ fj, lozenge. o, lateral scars. 



.1 1 1 • A. cardinal Imttress. p, post median scars. 



a COnSlCierablV m- ;. umbonal chambers. 9, crown j 



" j. platfiirni. r, side [crescent, 



r-rpisprl knnwlodo-p /;. platform vaults. .?, end ) 



Cre<l»eu l\nu\\lLtli;fc; , median plate. t. transverse scars. 



m, median scars. «, archlct (vascular sinuses). 



nf tViivf tnrni Mtld ii, anterior scars. v, cardinal scars. 



OI Ullb lUllU, cUm o, lateral scars. lo, sub-cardinal scars. 



- p, post-median scars. 



have elsewhere ?, crowni 



r, side j crescent. 

 , J 1 s, end ) 



quoted a SUbSe- t. transverse scars. 



u, archlec (vascular sinuses). 



queutly expressed •:; ^{^;!i^^,^^. 



opinion of Mr. Davidson's, abandoning his earlier views on the value of this 



* On the TrimerellidiB, a Paleozoic Family of the Palliobranchs or Brachiopotia. By Thomas David- 

 son, Esq., F. R. S., F. G. S., etc., and Professor William King, Sc. D. Honoris Causa, Queen's University in 

 Ireland: Quart, Joura. Geol. Soc, vol. xxx. pp. 124-173, pis. xii-xix. 1874. 



