314 
Balanus campbelli is nearly related to Balanus decorus Darwin; 
but the structural differences in the opercular plates and the pari- 
eties are so great that they seem to be distinctly separated. As to 
the body a comparison is not yet possible, as details of Balanus 
decorus are missing. 
Subgenus Eubalanus n. nom. 
[— Subgenus Balanus (Da Costa) Pilsbry]. 
Balanus amphitrite Darwin. 
Forma communis Darwin. 
Off Cavite, Manila Bay; ab. 5 fathoms. 13/11 14. Four quite small spec- 
imens on a small plate of muscovite. 
Cebu; muddy beach at low tide. 21/11 14. Several small specimens on 
gastropode shell inhabited by a hermit crab. 
Off Jolo; ab. 20 fathoms, Lithothamnion. 17/III 14. Some small spec¬ 
imens on a gastropode shell. 
Off Jolo; ab. 25 fathoms, sand and coral. 20/III 14. One specimen on a 
gastropode shell. 
Off Jolo; 20—30 fathoms, sand and corals. 20/III 14. Several specimens 
together with Balanus minutus, Balanus amaryllis, and Acasta 
conica. 
Some of the latter specimens in colour approach the forma 
cirraia Darwin, but the opercular plates, the mouth parts, and the 
cirri agree with the typical forma communis ; there are three dent- 
icles on each side of the notch in the labrum. 
Forma hawaiiensis nov. 
Kaladis Point, Mindanao; on the mole. 11/III 14. Two specimens. 
Pearl Harbour, Honolulu; on the coast. 5/V 15. Several specimens on 
broken china. 
This form of Balanus amphitrite somewhat recalls the forma 
albicostata, and inexpectata of Pilsbry (1916). 
The shape of the barnacles is rather regular, the rostrum all 
but straight or with its apical part a little outwards bent, so that 
the profile is somewhat concave; the other compartments, and 
especially the carina are rather convex. The parieties are white with 
dark violet or greyish-blue radiating stripes, sharply defined. Gen¬ 
erally a broader white zone runs along the median line of the com- 
