246 JOURNAL Of CONCHOLOGY, VOL. 9, NO. 8, OCTOBER, 1899. 



7. D. sericata Reeve, 1850; + Felania sericata Cpr., 1863. 

 Range. Gulf of California. 



8. D. nitens Reeve, 1850. 

 Range. Bay of Guayaquil. 



Section Phlyctiderma Dall. 



9. D. caelata Reeve, 1850. 

 Range. Bay of Guayaquil. 



10. D. semirugosa Dall, nom. nov. =' D. semiaspera Cpr., 

 Mazatlan Catalogue, p. 102, 1857, not of Philippi, 1836. 



Range. Gulf of California. 



This species is more globose than the West Indian form, and the 

 external sculpture, when perfect, is of a different character. Worn 

 specimens were confounded with Philippi's species by Carpenter. 



NOTES. 



Lucina leucopha^ata Reeve, 1850, of which the locality is un- 

 known, may, perhaps, belong to the West American fauna, and is 

 certainly a Diplodonta. 



L. guaraniana and L. porteziana d'Orbigny, 1846, from 

 Rio Janeiro, and L. patagonica d'Orbigny, 1842, from San Bias, 

 on the Argentine coast, appear to belong to the typical section of 

 Diplodonta, but I have not been able to examine specimens. 



Diplodonta puncturella Dall, n.sp., is a small species resemb- 

 ling D. capaloides Gabb, but less turgid, and having the entire surface 

 closely, regularly, microscopically punctate. Alt., 67 ; lat. 6*5 ; 

 diam. 4'o mm. It is also found in the Oligocene Bowden Beds of 

 Jamaica, and will be fully described and figured elsewhere. 



D. platensis Dall, n.sp. 



Shell small, solid, turgid, subequilateral, with prominent beaks, 

 wider than high, the anterior end more pointed and longer than the 

 other ; surface sculptured with fine concentric wrinkles most elevated 

 anteriorly and on the disc more or less alternately broken up, forming 

 an irregular chequered pattern; hinge plate narrow, teeth and liga- 

 ment normal, adductor scars very large and extending nearly to the 

 base ; pallial line and margin simple ; colour yellowish white. Alt., 

 n'5 ; lat., 13*0; diam., io - o mm. 



The posterior adductor scar, though extending far down, is not, as 

 in Sphcerella, separated by a gap from the cardinal region. 



