BABNACLES FROM THE NORTH PACIFIC HEXRY 227 



and separated from the other plates by a wide membrane; fork with 

 two long and diverging branches; internal lunbonal tooth on each 

 scutum; and two filamentary appendages on each side. As the only 

 real difference between this species and L. anatifera is the presence 

 of teeth on both scuta and as tliis character is variable, L. marocannus 

 must be considered a synonym of L. aiuitijera^ and until a more 

 comprehensive study is made of this species it does not seem advisable 

 to call it a variety. 



The specimens described below were obtained from six localities 

 between Willapa Harbor, Wash,, and the Aleutian Islands, and all 

 have an internal umbonal tooth on both scuta. 



Description. — The scutum is radially striate. The ridge from the 

 umbo to the apex is never very prominent and in some can scarcely be 

 seen. The occludent margin is nearly straight. The internal tooth of 

 the right scutum is usually larger than that of the left. The internal 

 basal rim does not quite i*each the carinal border. The carina is 

 separated by a rather wide interspace from the other valves ; the apex 

 is rounded ; the greatest width is at the middle, and the narrowest part 

 is just above the fork. The fork is narrower than the widest part of 

 the carina ; the run between the prongs is reflexed. A thick membrane 

 borders the occludent margins of the scuta and terga. The two occlu- 

 dent margins of the terga are nearly at right angles to each other. 



The peduncle varies in length in proportion to the length of the 

 capitulum. In young specimens tiny spines occur on the surface as 

 described by Darwin for the young of L. austivJis. In older specimens 

 no spines were found, but there are irregular chitinous plates scattered 

 over the peduncle. There are two filamentary appendages on each 

 side. The mouth parts and cirri do not differ fi^om those of typical 

 Lepas anatifera. The caudal appendages are small and roimded at the 

 apex. 



&ize. — In the largest specimen the capitiilmn is 43 mm. in length 

 and 28 mm. in width, and the peduncle is 50 mm. in length and 13 mm. 

 in width (dry specimen. "Willapa Harbor) . 



Localities. — Willapa Harbor, Wash., July 15, 1938, on limb washed 

 on shore. Harriet Harbor, Moresby Island, British Columbia, July 

 29, 1934, on kelp with L. pectinata paeifiea. William Head, Vancouver 

 Island. British Columbia. 1926, from ship's bottom. Friday Harbor, 

 Wash.. July 14, 1937. on floating board with L. pectinata paeifiea. 

 Lousonne Harbor. Queen Charlotte Island. British Columbia. Febru- 

 ary 11, 1935, on floating bottle. Aleutian Islands, 1936. 



