18 PROCEEDINGS OF THE NATIONAL MUSEUM VOL, 126 
T Il Iil IV Vv VI 
a Pp a p a Pp a Dp a 7) . a p 
n 4 4 4 4 4 4 4 4 4 3 2 4 
R 17-21 13-18 13-16 10-13 12-15 11-14 25-29 29-31 26-32 31-35 29-32 28-34 
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The penis is annulated throughout its length, but it is sparsely 
hirsute except for the distal extremity (fig. 32). The basidorsal point 
is small, bluntly rounded, and sparsely covered with short, stiff 
bristles. 
Remarxs.—Balanus stultus is herein assigned to the subgenus 
Megabalanus. Darwin (1854, p. 216), however, obviously could not 
reconcile the morphological evidence with the sectional (=subgenus) 
diagnosis he proposed for other megabalanids, and, consequently, 
he was forced to assign B. stultus to a different section of Balanus, 
subsequently regarded as the subgenus Conopea. Pilsbry (1958, 
p. 27) also could not accept the fact that B. stultus is a megabalanid; 
he stated: 
In Florida when I first saw these barnacles I thought they were a species of 
Megabalanus (the B. tintinnabulum group), but the absence of pores in the radii 
was against this view. Later, upon identifying them as B. stultus, I was amused 
to find that Darwin had been similarly embarrassed by the structure of this 
barnacle. 
The failure of earlier workers to note the obvious affinities of B. 
stultus stems from the fact that the tubes of the radii are not readily 
observed unless the radius is broken away from the parietes. Particu- 
larly significant, in regard to facies similarity, are the form and topog- 
raphy of the opercular valves and the structure of the trophic as well 
as the cirral appendages. It should be pointed out at this time, however, 
that there are at least two recognizable species groups in the mega- 
balanids that are based in part on certain elements of the mouth field 
and on certain shell and opercular characters. Some semblance of 
these two groups may be seen in the key to the species of Megabalanus 
presented by Pilsbry (1916, p. 53). Of these groups, B. stultus perhaps 
is allied most closely to the B. tintinnabulum group. 
The specimens that Pilsbry (1927, p. 38) reported as Tetraclita 
radiata were subsequently reexamined by Nilsson-Cantell (1939, 
p- 5), who found them to be specimens of B. stultus. It would also 
appear that the specimen Pilsbry cites and illustrates in the same 
paper as B. tintinnabulum antillensis, growing on Millepora alcicornis, 
may also prove, on closer scrutiny, to be a specimen of the present 
species. 
In a recent paper, Kolosvaéry (1966) reported the occurrence of 
what he believed to be a new subspecies of B. studtus from Cuba, 
which he called morycowae. The cardinal differences between mory- 
cowae and the nominate subspecies is that, in the former the adductor 
