SPIRIFERID^. 



125 



De Koninck) a Carboniferous form, with a small hinge-area, as well as for Retzia vera, 

 Hall, and some others, he would retain the generic designation of Retzia ; while for 

 certain forms which, according to his views, have more nearly the characters of R. Adrieni, 

 he proposes the new generic designation of Trematospira (types, T. perforata and 

 T. multistriata, Hall). For those species typified by R. formosa. Hall, R. Bouchardii, 

 Dav., and R. Salteri, Dav., he would propose the genus Rhtnchospira.^ He con- 

 cludes his notice on the genus Retzia by obsemng that his remarks have been made 

 more with the intention of calling the attention of palaeontologists to the characteristics 

 observ ed in several species than of finally determining the question of the generic rela- 

 tions among the several groups. 



I am quite ready to allow that Prof. King's diagnosis is defective, since, as above 

 stated, none of his several types possess " the triangular area and closed fissm'e ;" but, 

 for all that, we are bound to consider T. Adiieni as the type of the genus, and, if 

 necessary, to alter the defective portions of the diagnosis. R. serpentina, it is true, was 

 rightly or wrongly added by myself, Dr. S. P, Woodward, and some other palaeontologists 

 to the species of Retzia, on account of its small hinge-area and punctured shell ; and 

 consequently, if Prof. Hall can show that its characters are distinct from those of R. 

 Adrieni, it would require to form the type of a new genus. Retzia would therefore be 

 a Terebratida-shaped shell, with a small circular foramen at or near the extremity of the 

 beaJc, more or less completely surrounded by a deltidium in two pieces. Surface ribbed or 

 striated. Shell-structure punctate. Interior with diverging spiral lamella. Tj'pes, R. 

 Adrieni, R. Salteri, R. Bouchardii, &c. It is a Palaeozoic genus as far as we at present 

 know ; but much has still to be found out with reference to its internal arrangements, as 

 well as whether the small hinge-area of R. (?) serpentina and R. vera would of itself afford 

 sufficient grounds for the establishment of a separate genus. 



Retzia Salteri, Davidson. PI. XH, figs. 21, 22. 



Terkbratula Salteri, Dav. Bull. Soc. Geol. France, 2nd ser., vol. v, p. 331, pi. iii, 

 fig. 31, 1848. 



Retzia Salteri, Schmidt. Sil. Form. Ehstland, &c., p. 212, 1858. 



— — Salter. Siluria, 2nd edit., p. 250, Foss. 57, fig. 7, 1859. 



— Baylei, Lindstrdm. Gottlands Brachiop. ; Ofvers. K. Vet.-Akad. Forhandl., 



p. 337, I860. 



Spec. Char. Transversely oval or sub-pentagonal, wider than long, greatest breadth 

 posteriorly ; hinge-hne very obtuse ; sides rounded, indented at the middle in front. 



^ Prof. Hall writes me, that, while describing his genus Trematospira, he had forgotten to refer to my 

 Rhynchonella Salteri, and that his American types of Trematospira have two very little ribs in the middle 

 of the valve, as in Rk. Salteri, and that he now feels at a loss whether or no to refer to Terebratula ferita 

 as the type of Retzia. 



