84 BULLETIN 60, UNITED STATES NATIONAL MUSEUM. 



d. A narrow area between the ridge from umbo to apical angle of scutum, and 



the oecludent border P. ksotipferi. 



(Id. A rather wide area between the ridge and the oecludent margin. 



P. kasmpferi litiun. 



Subgenus PCECILASMA s. str. 



Smoothish forms with narrow carina and surface sculpture of fine 

 engraved strife, the scutum not slit; living- chiefly on the carapaces of 

 crabs. The species are closely related and variable, and their deter- 

 mination is difficult. The capitulum is often bilaterally asymmetrical. 

 All known American forms are figured on Plate VI. 



PCECILASMA K/EMPFERI Darwin. 



Plate V, tigs. 10, 11; Plate VI, tigs. 3, 4, 5. 



1851. Pu'dlasma kxmpferi Darwin, Monograph on the Cirripedia, Lepadidee, 

 p. 102, pi. II, tig. 1' (Japan, on Imtcltus kitmpferi) . — Pilsbry, Bulletin of the 

 Bureau of Fisheries, XXVI, 1907, p. 183 (Hawaiian Islands). 



Locality. — Cat. No. 28653, U.S. N.M. ^2i^2iYi,on Kmmpferiaksemp- 

 feri. 



The largest of three capitula measures, length 14, width 8.5, diame- 

 ter 4.3 mm. Carina 9 mm. long. Peduncle 6.5 mm. long. The left 

 scutum is somewhat mor& convex than the right. The scuta have 

 distinct radial stria^ and some concentric grooves. 



Internally the scuta have strong umbonal teeth and a rather narrow, 

 smooth, and rounded basal callous rib (Plate VI, fig. 3). The carina 

 (figs. 4, 5) is concave inside, the concavity decreasing toward the 

 base. The teeth at its baso-scutal angle are very small, and in the 

 example examined, asymmetrical. 



The mandible of No. 28653 has four teeth and a small lower point, 

 the upper two teeth widely spaced. There is a small beard on the 

 lower margin, scarcely any on the upper (Plate V, fig. 11). 



The maxilla (Plate V, fig. 10) has two large upper spines, the edge 

 deeply notched below them, sparsely spiny in the notch. It then pro- 

 trudes and is rather closely set with spines. 



Cirri are about as figured for Megdlnsma annandalei. 



M. Gruvel, in his report on the Trava/Ueui' and Talisman Cirripedes, 

 has considered P. anrantia Darwin a variety of P. I'sempfpri^ stating 

 tliat of seven examples taken oflf Cape Bojador in 410 to 782 meters, 

 part had characters of the one, part of the other form." No western 

 Atlantic examples I have seen agree entirely with the Japanese or 

 eastern Atlantic forms, as defined by Darwin and Gruvel; and while 

 their differential characters are not of great importance, yet it seems 

 desirable that they be put on record. 



«See Znol.Trav. et Talism., Cirrhipedes, p. 46, pi. iv, fig. 1. 



