226 PROCEEDINGS OF THE NATIONAL MUSEUM vol.88 



Genus LEPAS Linnaeus 



LEPAS ANATIFERA Linnaeus 



FiGUKE 1 



Synonymy : See Nilsson-Cantell, 1921, p. 236. 



This is one of the most variable species of the genus Lepas. The 

 number of filamentary appendages, i. e., one at the bases of the first 

 cirri and one on the prosoma on each side, is the most reliable criterion 

 in differentiating this species from the closely related species, L. hillii. 

 Darwin states that the presence of a tooth beneath the umbo, on the 

 right-hand scutum, and its entire absence on the left constitute an 

 unfailing diagnostic mark. Weltner (1900) found otherwise typical 



FiGCBB 1. — Lepas anatifera from Harriet Harbor, British Columbia: a. Side view, X 2; 

 b, carina, external view, X 3 ; c, apex of capitulum from above, X 3. 



L. anatifera with an internal tooth on the left-hand scutum as well. 

 Nilsson-Cantell (1928) examined specimens that Cornwall (1925) 

 identified as L. hillii from British Columbia and found an internal 

 umbonal tooth on both scuta. In 1931 this author also described an 

 atypical form, the scuta of which have no umbonal teeth. The ab- 

 sence of umbonal teeth is also one of the diagnostic characters of sev- 

 eral varieties; subspecies indica Annandale (1909) has an internal 

 umbonal tooth on the left-hand scutum only. Therefore it can be seen 

 that this character is an extremely variable one. 



Miranda y Eivera (1921) proposed a new species, L. marocannus^ 

 witli the following characters : Plates p.mooth ; carina slightly curved 



