234 balanim:. 



Mouth : labrum finely hairy, but without any teeth ; mandibles, 

 with the 4th tootli small ; the 5th confluent, with the sometimes 

 smooth, sometimes pectinated inferior angle. Maxillae, rather broad, 

 with a slight notch under the upper pair of spines. Cirri, first pair, 

 with one ramus, having 29 segments, and above one third longer than 

 the shorter ramus, having 1 7 segments ; these latter segments are 

 remarkable by the extent to which their upper front surfaces are 

 laterally produced into projections, twice as long as the breadth of that 

 portion of the segment which is articulated to the adjoining segment. 

 These projections have a double row of serrated spines on their upper 

 edge, and a beautiful radiating bundle at the end ; the projections de- 

 crease in length, both in the upper and lower segments. The second 

 cirrus (PI. 29, fig. 4) has the segments (13 in number, in the same 

 individual with the segments above enumerated) of both rami 

 produced in the same singular manner as in the first pair. The third 

 pair have only inverted conical segments, coloured darker purple than 

 the other cirri. The sixth pair had in the same individual 31 or 32 

 segments, and therefore one or two more than in the longer ramus of 

 the first pair.* The segments in the posterior cirri have their anterior 

 faces shield-shaped, and bear 6 or 7 pairs of spines, with some minute 

 intermediate spines. There is the usual point at the dorsal basis of the 

 penis. 



Range. — This species is common on the southern shores of England 

 and in the Channel Islands : the largest specimens which I have seen 

 came from these quarters. The most northern point whence I have 

 seen specimens, is Tenby, in South Wales. This species is common 

 throughout the Mediterranean ; I have seen specimens from Malaga, 

 Sicily, Algiers, and Smyrna ; thence it ranges down the western coast 

 of Africa, as far south as the Gambia and Loanda, in 9° south latitude. 

 I believe British specimens are more often corroded than those from 

 further south. Amongst some old, ill-kept specimens in a box in the 

 British Museum, marked "Kingston, Jamaica," there were some of 

 this species : also I received some specimens, marked " S. America," 

 from Mr. G. B. Sowerby : again, Ellis, in Phil. Trans., vol. 50, part 

 11, gives a figure (Tab. 34, fig. 15) of some specimens from the West 

 Indies, which I believe to be B perforates : hence, it is in some de- 

 gree probable that this species, like B. tintinnabulum, and amphitrite, 

 and improvises, may be found on both sides of the equatorial Atlantic. 

 Balanus perforatus is attached, together with B. tulipiformis, trigonus, 

 amphitrite, Chthamalus stellatus, and Pollicipes cornucopia, usually to 

 rocks, near the lower limit of the tidal level ; but I believe, from 

 specimens kindly sent me by Mr. Mac Andrew, that it is frequently 

 obtained by dredging ; one specimen was even marked 30 fathoms. 

 According to Poli, it is sometimes attached to the bottoms of vessels ; 

 and I have seen a specimen adhering to the floating Lepas HUH. 



Affinities. — This is a distinct species, closely allied to no other 

 species, but comes nearest to B. Icevis, which is its representative in 



* Under the Genus (p. 190) I have given the numbers of the segments in 

 the cirri of this species at successive ages. 



