346 TESTACEOUS MOLLUSCA. 



Saxicava Pholadis, p. 50, t. 9, f. 5 ... 8. Guerini, p. 51, 1. 12, f. 2 ... 

 S. Carditoides, p. 51, t. 12, f. 53 ... S. Calif ornica, p. 51, t. 12, 

 f. 54. 



On Petricola (p. 51). Sowerby, in his ' Thesaurus,' has published 

 a monograph of this genus. Our P. bidentata (p. 54) should be 

 transferred to Montacuta, adopted and defined at p. 40. 



Petricola semilamellata, p. 52, t. 11, f. 41 ... P. striata, p. 52, 

 t. 11, f. 42 ... P. costellata, p. 52, t. 11, f. 43 ... P. Roccellaria, 

 p. 52, t. 11, f. 44 ... P. ruperella, p. 52, t. 11, f. 45 ... P. Pholadi- 

 formis, p. 52, t. 13, f. 49 ... P. dactylus, p. 53, t. 13, f. 26. 



Venerupis exotica, p. 54, t. 9, f. 29 ...- V. crenata, p. 55, t. 12, f. 58 

 ... V. Lajonkairii, p. 55, t. 12, f. 55. Consult the monograph in 

 Sow. Th. vol. 2. 



Sanguinolaria Nuttalii, p. 56, 1. 12, f. 56 ... S. Calif orniana, p. 56, 

 t. 12, f. 57 ... 8. livida, p. 57, t. 11, f. 52. 



On Psammotjea and Psammobia. The former genus should be 

 suppressed, since its members, when in perfect condition, exhibit a 

 very different hinge from that assigned to them in the definition. 

 P. violacea, zonalis and rosea may be transferred to Psammobia, 

 P. Candida and P. Tarentina (the figure of the latter in Delessert is 

 marvellously like Petricola ocliroleuca, p. 52, a Tellina in our opinion, 

 which must resume its Linnean name fragilis) to Tellina ; P pellu- 

 cida is the same as T. lanceolata, p. 67, and P. Donacina (judging 

 from the cited figure) seems a Donax. Psammobia Cayennensis, 

 p. 58, is a true Tellina; Tellinides striata, p. 74, perchance, a Psam- 

 mobia. For additional Psammobia. consult Proc. Bost. vols. 2, 3, 

 Zeit. Mai. 1846, 1848, Gray's Appendix to DiefTenbach's New Zealand, 

 Philippi's ' Abbildungen, &c. Conchylien,' and, with great caution, 

 Adams's Jamaica Shells. 



Psammobia maculosa, p. 57, 1. 11, f. 28 ... P. elongata, p. 57, 1. 11, 

 f. 46 ... P. squamosa, p. 57, t. 11, f. 47 ... P. Cayennensis, p. 58, 

 t. 11, f. 48 ... P. Tellinella, p. 58, t. 11, f. 11 ... P. fragilis, p. 58, 

 t. 11, f. 49 ... P. Galatea, p. 58, t. 13, f. 44 ... P. violacea, p. 59, 

 t. 11, f. 20 ... P. costata, p. 59, t. 11. f. 12 ... P. lineolata, p. 59, 

 t. 14, f. 1 ... P. Pacifca, p. 60, t. 12, f. 59. 



Galeomma Turtoni, p. 59, t. 9, f. 41 ... G. aurantium (as Psam- 

 mobia a. p. 58), t. 9, f. 25. 



Psammot&a violacea, p. 60, t. 12, f. 60 ... P. zonalis, p. 60, t. 11, 

 f. 50 ... P. pellucida, p. 60, t. 14, f. 26 ... P. Tarentina, p, 60, t. 11, 

 f. 56 ... P. Donacina, p. 60, t. 11, f. 57. 



On Tellina (p. 61). The following less generally recognised 

 Lamarckian species have been noticed or delineated in my monograph 

 of the genus: T. crucigera (p. 61), f. 78, 79, 178; T. rosea (p. 63), 

 f. 218 (as Madagascariensis) ; T. elliptica (p. 63), as = acuta (p. 67) ; 



