122 BULLETIN 93, UNITED STATES NATIONAL MUSEUM. 



BALANUS L.EVIS NITIDUS Darwin. 



Plate 27, figs. 2-2d; 4,5. 



Among the very numerous specimens examined from northern Chile 

 (Arica) and Peru, none have the broad scutal furrow of Magellanic 

 Isevis and the epidermis is wholly or largely wanting. The number of 

 scutal furrows in the two largest series examined is as follows : 



The furrows are narrower than in southern B. Isevis, and often one 

 or both are very lightly impressed. A third furrow when present is 

 only weakly indicated. The pit in the scutum for the lateral depres- 

 sor muscle is often larger in nitidus than in Iszvis. 



B. I. nitidus is common on the gastropod Concliolepas concholepas. 

 Where crowded the usual diameter of the barnacles is 10 to 12 mm. 

 Conic, unhampered individuals of the same group have a basal diam- 

 eter of about 13 mm. Small pebbles are sometimes completely cov- 

 ered, appearing like balls of barnacles (pi. 27, fig. 4, Callao). 



BALANUS L^EVIS COQUIMBENSIS Sowerby. 

 Plate 28, fig. 4. 



1846. Balanus coquimbensis G. B. SOWERBY, in Darwin's Geological Observa- 

 tions, p. 264, pi. 2, fig. 7. 



1854. Balanus Isevis var. coquimbensis Sowerby, DARWIN, Monograph, p. 227, 

 pi. 4, fig. 2a. 



Type-locality. Inland from Herradura Bay, Coquimbo, Chile, in a 

 Pleistocene deposit. 



Distribution. Strait of Magellan to Coquimbo. 



