BALANUS. : 21 
5. Bauanus porcatus. Tab. I, fig. 5a—b5g. 
BaLanus porcatus. Emanuel da Costa. Hist. Nat. Test. Brit., p. 249, (1778). 
Lepas BALANUS. Jinn. Syst. Nature, (1767). 
— — Born. Testacea Mus. Cees. Desc., Tab. 1, fig. 4, (1780). 
— — Chemnitz. Syst. Conch., 8 Band., Tab. 97, fig. 820, (1785). 
BaLaNUS ARCTICA PATELLIFORMIS. lis. Philosoph. Transact., vol. 50, Tab. 34, 
fig. 18, (1758). 
— suLcaTus. Bruguiére. Encyclop. method., Tab. 164, fig. 1, (1789). 
Lepas cosTaTa and BaLanus. Donovan. British Shells, 1802-1804, Tab. 30, fig. 1, 2. 
Lepas Scortca. W.Wood. General Conchology, Pl. 6, fig. 3, sed non Lepas balanus, 
Pl. 7, fig. 3, (1815). 
BaLanus aNGuLosus. Lamarck (1818), in Chenu, Illust. Conch., Tab. 11, fig. 11. 
— TESSELATUS. Sowerby (!) Mineral Conchology, Tab. 84, (1818). 
— Scoticus. Brown. [Illust. Conch. Great Britain, Pl. 7, fig. 2, sed non 
Pl. 6, fig. 9 et 10 (1827) : 2d edit., Pl. 53, fig. 1-3, 22, 23 et 
Pl. 54, fig. 1-3. 
— GENIcULATUS. Conrad. Journal Acad. Philadelphia, vol. vi, part 2, p. 265 
(1830), Tab. 11, fig. 16. , 
— — Aug. Gould (!) Report on the Invertebrata of Massachussetts, 
fig. 9 (1841). 
B. parietibus, sed non basi, poris perforatis; testa alba, plerumque longitudinaliter 
acute costata ; radiorum marginibus superioribus pene basi parallelis: scuto longitudinaliter 
striato ; tergi apice producto, purpureo. 
Parietes, but not the basis, permeated by pores; shell white, generally sharply ribbed 
longitudinally ; radi with their summits almost parallel to the basis. Scutum longitudi- 
nally striated ; tergum with the apex produced and purple. 
Fossil in the Glacial deposits of Scotland (Isle of Bute), of Uddevalla, and (Beaufort) Canada. In the 
Mammaliferous Crag (Bramerton, Thorpe) and Red Crag (Sutton) ; Mus. Lyell, J.deC. Sowerby, 8. Wood, 
Bowerbavk, &c. 
Recent, England, Ireland, Scotland, Shetland Islands, Iceland, Davis’s Straits, 66° 30’ N.; Lancaster 
Sound, 74° 48’ N. Maine and Massachussetts, United States. China (?) In deep water, commonly 
adherent on shells, crustacea, and rocks. 
This species can be at once distinguished from all the foregoing by the basis being 
solid or not perforated by pores; and from all the following species, with the exception of 
B. crenatus, by the parietes having large square pores or tubes. From B. crenatus, this 
species can be distinguished by its longitudinally striated scuta, purple-beaked terga, and 
by the peculiar structure, immediately to be described, of its parietal pores; and in most 
cases even by its general aspect, larger size, and ribbed walls. When, however, 
B. porcatus and crenatus have grown together on the same irregular surface, for instance, 
on a Pecten, they sometimes resemble each other in a very deceptive manner. The 
opercular valves have not certainly been found fossil, but I have given drawings from recent 
specimens. | 
