THE NAUTILUS. 



VOL. XXIV. MARCH, 1911. No. 11 



SOME NOTES ON THE OLIVIDAE-III. 



BY CHARLES AV. JOHNSON. 



The occidental species of the genus Oliva, from shell characters 

 alone, seem to divide into two groups, the one containing the larger 

 and beautiful 0. porphyria Linne and the smaller splendidula Sowb., 

 found only on the Pacific side from Panama to Mazatlan. The 

 other, a group of analogous species, is represented on the Pacific side 

 by 0. spicata Bolten, peruviana Lam., incrassata Sol., and julietta 

 Duel., and on the Atlantic side by 0. reticularis Lam. circinata 

 Mart, and fulyurator Bolten. It is as difficult to clearly define the 

 species on this coast as on the other, and specimens of 0. spicata and 

 reticularis often very closely resemble each other, thus indicating a 



common origin. 



OLIVA SPICATA (Bolten). 



Porphyria spicata Bolt., Mus. Boltenianum, p. 35, 1798. 



Porphyria arachnoidea Bolt., /. c. p. 36, 1798. 



Oliva araneosa Lam., Ann. du Mus. XVI, p. 315, 1810. 



Both Bolten and Lamarck refer to the same figure by Martini 

 (Conch. Cab., II, tab. 48, fig. 509) and Bolten refers to it a second 

 time under arachnoidea. In adopting Lamarck's names, venulata (p. 

 313) should have been the species, as it appeared before arantosa (p. 

 315). The first figure referred to by Lamarck under venulata is in 

 the Encycl. Meth., pi. 361, f. 5; the second reference is to Martini 

 (II, tab. 46, f. 488) and happens to be the figure on which Bolten 

 based his litterata. It includes the oblong forms scarcely separable 



