566 CAMBEIAN BKACHIOPODA. 



out a bit of the shell which gives rise to the narrow, deep furrow described by Waagen. The 

 ventral valve has (a) a false area beneath the apex, and (b) a true area on a plane with the 

 margins of the valve. 



When looking over the types of Neoholus and LaMimina for the purpose of having illus- 

 trations made of them, I noted that there was a strong resemblance between the shells of the 

 two genera, but having the impression that the ventral valve of LakJiwina had a pedicle open- 

 ing at the apex, drawings were arranged on the plates under the conception that LakJimina 

 belonged with the Neotremata. Schuchert noted the same resemblance when looking over 

 the plates of this monograph and called mj^ attention to it. I then made a careful study of 

 all of the specimens and by the use of acid developed several interiors of dorsal valves. I 

 found that the supposed perforation of the apex of the ventral valve of LakTimina was the 

 result of the breaking out of the minute apex; that the dorsal valve of Neoholus warthi was 

 the same as the dorsal valve of Lakhmina linguloides and that two genera and four species had 

 been based on specimens of Neoholus warthi. 



The external characters of all of the shells referred to Neoholus and LakTimina are the 

 same. Only one specimen of the interior of the ventral valve that shows anything of the 

 platform beneath the visceral area occurs in the collections; this was referred to LakTimina 

 by Waagen, but the accompanying dorsal valves were first described as Neoholus. By com- 

 paring the illustrations of Waagen [1891, PI. II] the student will notice that figure 8c of the 

 interior of the dorsal valve of Neoholus is essentially the same as the interior of the dorsal valve 

 of LakTimina (fig. 4c) with the exception of the thickened platform. 



It may seem as though it were forcing unlike forms into one species to place the specimen 

 represented by Plate LXXXI, figures 2f, 2g, and 2h, with those represented by figures 47A 

 and 47B, page 567, but with our present information it appears to be necessary to do so. 



All authors have classified the shells described as LakTimina linguloides with TnmereUa, 

 and Hall and Clarke [1892c, p. 29] state that in the present condition of knowledge it must 

 be regarded as the earliest representative of the trimerelloid Brachiopoda. The external form 

 is similar to that of Oholus and the interior characters might readily have been developed from 

 that genus, but the platform is posterior and not central as in the trimerelloids. 



Neobolus warthi Waagen. 



Text figures 47A-B, page 567; Plate I, figures 3, 4, 4a-b, 5, 5a; Plate LXXXI, figures 2, 2a-h. 



Neobolus warthi Waagen, 1885, Mem. Geol. Survey India, Paleontologia Indica, 13tli ser., Salt Range Fossils, vol. 1, 

 pt. 4, fas. 5, pp. 758-759, PI. LXXXIV, figs. 3-8. (Described and discussed as a new species. The three 

 specimens represented by figs. 4, 5a-b, and 7 are redrawn in this monograph, PI. I, figs. 4, 4a, and 3, respec- 

 tively.) 



Neoholus wynnei Waagen, 1885, idem, pp. 759-761, PI. LXXXV, figs. 1 and 2. (Described and discussed as a new 

 species. The two specimens represented by figs, la-c and 2a-c are redrawn in this monograph, PL I, figs. 5 

 and 5a, respectively.) 



Davidsonella linguloides Waagen, 1885, idem, pp. 764-766, PL LXXXV, figs. 3-6. (Described and discussed as a new 

 species. The four specimens represented by figs. 3a-b, 4a-b, 6, and 5 are redrawn in this monograph, PI. 

 LXXXI, figs. 2, 2d, 2e, and 2f-h, respectively.) 



Davidsonella squama Waagen, 1885, idem, pp. 766-767, PL LXXXVI, fig. 1. (Described and discussed as a new 

 species. In 1891 [PL II, figs. 6a-b] Waagen figures the specimen represented by figs, la-b as Neobolus warthi. 

 The specimen represented by figs, la-b is redrawn in this monograph, PL LXXXI, fig. 2a.) 



Neobolus warthi Waagen, Oehlert, 1887, Manuel de conchyliologie, by Fischer, p. 1263, fig. 1012. (No text refer- 

 ence. The two figm'es are copied fi-om Waagen, 1885, PL LXXXIV, figs. 6 and 7.) 



Lakhmina linguloides (Waagen), Oehlert, 1887, idem, p. 1265, fig. 1015. (No text reference. The two figures are 

 copied from Waagen, 1885, PL LXXXV, figs. 5 and 6.) 



Lalhmina linguloides Waagen, 1891, Mem. Geol. Siu-vey India, Paleontologia Indica, 13th ser.. Salt Range Fossils, 

 vol. 4, pt. 2, PL II, figs. 3a-c and 4a-c. (No text reference. Figs. 3a-b and 4a-b are copied from Waagen, 1885, 

 PL LXXXV, figs. 3a-b and 4a-b, respectively; figs. 3c and 4c are copied from Waagen, 1885, PL LXXXV, 

 figs. 6 and 5, respectively.) 

 Neobolus warthi Waagen, 1891, idem, PL II, figs. 5-9. (No text reference. Figs. 5, 6a-b, 8a-b, and 8c are copied 

 from Waagen, 1885, PL LXXXIV, fig. 4; PL LXXXVI, figs, la-b; PL LXXXIV, figs. 5a-b; and PL LXXXIV, 

 fig. 7 ; respectively. The specimen figured by Waagen, 1885, PL LXXXVI, figs, la-b, as Davidsonella squama 

 is figured by him later, 1891, PL II, figs. 6a-b, as Neobolus warthi.) 



