De PROCEEDINGS OF THE NATIONAL MUSEUM VOL. 125 
of T. divisa; however, these barnacles remain poorly known because 
earlier workers failed to provide detailed descriptions and illustrations 
of their distinctive features, especially of the mouth field and cirral 
appendages. The addition of such information, provided herein for 
the Dominica fauna, should aid materially in an understanding of the 
morphological and biological characters of other populations of the 
same species as well as closely related species in the Caribbean and 
elsewhere. 
The dissected specimens, which have been figured, are deposited 
in the collections of the American Museum of Natural History 
(AMNH). Representative samples of all the species have been placed 
in the collections of the American Museum and the U.S. National | 
Museum (USNM). | 
The author is indebted to Drs. Ernst Kirsteuer and Klaus Riitzler, 
who made these collections available for study. Dr. Wiliam K. 
Emerson of the American Museum kindly read a manuscript draft 
of this paper and offered several suggestions for improvement. Dr. 
William A. Newman, Scripps Institution of Oceanography, first 
brought to the writer’s attention the fact that Balanus stultus was 
a megabalanid. The writer should also like to thank Dr. Newman 
for many informative discussions on the systematics, evolution, and 
phylogeny of the Cirripedia. 
Family CHTHAMALIDAE Darwin, 1854 
Genus Chthamalus Ranzani, 1817 
Chthamalus angustitergum Pilsbry 
Figure 1 
Chthamalus stellatus angustitergum Pilsbry, 1916, p. 305, text-figs. 85, 86, pl. 71, 
figs. 5, 5a, 5b; 1927, p. 37, fig. 1—Nilsson-Cantell, 1933, p. 506.—Kolosvary, 
1939, p. 161, figs. 6-1, 6-2; 1941, p. 68, fig. lsa.—Stephensen and Stephensen, 
1950, p. 389; 1954, p. 80.—Henry, 1954, p. 444.—Wells, 1966, p. 92. 
Chthamalus stellatus—Smith, Williams, and Davis, 1950, p. 134.—Marshall, 1953, 
p. 435.—Voss and Voss, 1960, p. 102.— Werner, 1967, p. 70. 
Chthamalus angustitergum.—Newell, Imbrie, Purdy, and Thurber, 1959, p. 209. 
Mareriau.—Western side of Panto Hole Bay, east of town of 
Marigot, approximately 15°32’21”N, 61°17’31"W; intertidal, on 
Tetraclita (Tetraclita) stalactifera; May 1-10, 1966; about 100 
specimens. 
Diaenosis.—Articular ridge of scutum straight to slightly convex, 
basal end of which evenly rounded and not projecting beyond the 
basitergal angle. Tergum narrow, about twice as high as broad, and 
nearly twice as thick as scutum. Mandible quadridentoid, with basal 
