COMPLETE GRAU : PECTINIDAE OF THE EASTERN PACIFIC 59 



3. Adanson (1757, p. 214, pi. 15, fig. 7) described a juvenile specimen 

 of the same shell, naming it VEssan and giving as the locality 

 ". . . la cote du Senegal." [Adanson pre-Linnean and invalid.] 



4. Chemnitz (1784, p. 298, tab. 63, figs. 601, 602) referred to the 

 descriptions and figures of Lister and Klein and adopted the name 

 Pseud-Amusimn. His own diagnosis of the shell, however, was 

 based on the shell his figures represented, a European species which 

 had been named and described eight years earlier: Pecten septem- 

 radiatus Miiller (1776, p. 248). Therefore Chemnitz' own des- 

 cription and figures must be disregarded; having cited the earlier 

 authors, he was obviously referring to their shell, and his assump- 

 tion that it was identical with the European species does not alter 

 that fact. Furthermore, the name Pseud-amusium is quite apropos 

 when applied to the circular and smooth west African species, but 

 not at all for the rather oblique and radially ribbed P. septemradia- 

 tus. [Chemnitz' specific names rejected by the International Com- 

 mission on Zoological Nomenclature as being non-binomial.] 



5. Gmelin (1791, p. 3318) cited the figures of Lister, Klein and 

 Chemnitz, named the shell Ostrea hybrida, and gave as type locality 

 ". . . in mari norwegico." Since that locality is correct only for 

 Pecten septemradiatus, it indicates that he did not see the shell of 

 Lister and Klein, but accepted Chemnitz' erroneous figures and 

 description. Thus Ostrea hybrida was actually the first binomial 

 name for the west African shell. 



6. Chemnitz (1795, p. 262, tab. 207, figs. 2037, 2038) described and 

 figured Pecten exoticus, which is identical with the shell of Lister 

 and Klein, giving as locality (obviously incorrect), "Red Sea." 

 Dillwj'n (1817, p. 259) first validated the name Ostrea exotica. 



7. Chemnitz (1795, p. 265, tab. 207, fig. 2043) described and figured 

 Pecten Danicus. Since his erroneous 1784 description and figures 

 for Pseud-amusium actually represented the common European 

 shell we know to have been previously named Pecten septemradia- 

 tus, it is obvious that he considered P. danicus a distinct species. 

 Several subsequent authors also did, others regarding it as a sub- 

 species of P. septemradiatus. However, P. danicus is really in the 

 synonymy of P. septemradiatus. 



8. Lamarck (1819, pp. 177-178) invalidly restricted Pecten hybridus 

 to the figures of Chemnitz cited by Gmelin, ignoring the fact that 

 the latter had also cited those of Lister and Klein. As a variety 

 Lamarck included the totally unrelated Ostrea squamosa Gmelin 



