REPORT ON THE CIRRIPEDIA. 39 



Though young specimens, they agree in all essential regards with the diagnosis and 

 description of Darwin. Two nearly full-grown specimens were taken from the screw in 

 September 1875, in the Pacific Ocean, about (Station 2(>9. The fork of the carina is 

 deeply embedded ; the uppermost part of the peduncle has lost its orange colour, which 

 may be due to the alcohol. Nor did I observe the yellowish beads on the chitinous mem- 

 brane at the base of the capitulum, as described by Darwin. As stated by this author 

 the filamentary appendages offer a good character, so I give, on PI. I., figures of the 

 basal articulation of the first cirrus, not only of this but also of the other species of this 

 genus. 



Lepas anserifera, Linn. (PI. I. fig. 4). 



Lepas anserifera, Lmna'us, Systema Naturae, 1767. 



,, ,, Darwin, Monograph Lepadidae, 1851, p. 81. 



On different occasions specimens belonging to this species were collected during the 

 cruise of H.M.S. Challenger. Sometimes only a few, and at the same time small, speci- 

 mens were collected ; but on two occasions numerous and large specimens were taken. 

 The former, probably, are young, while the latter, on the contrary, are full-grown and 

 mature, being moreover frequently furnished with ovigerous lamellae. As, however, their 

 capitulum is only 23 mm. at the utmost, they have not reached the size of the largest 

 specimen observed by Darwin, which had a capitulum one inch and a half (about 38 mm), 

 in length. In one other respect, some of the larger specimens (collected at Raine Island) 

 do not quite agree with Darwin's diagnosis ; their valves are not approximate, but 

 distinct, dark reddish- coloured interspaces being left between the scutum and tergum, 

 and still broader ones between the carina and scutum and tergum. These interspaces 

 do not occur in the smaller specimens, nor in the larger ones collected on the north coast 

 of New Guinea. 



The small specimens with approximated valves (Station 192) have a smooth carina ; 

 of the larger specimens (collected near Raine Island), the younger ones are furnished 

 with a barbed carina, the eldest and largest ones, on the contrary, with a smooth carina. 

 The small specimens (Station 192) have their occludent margin more rounded and their 

 capitulum less elongated than the larger ones. In all the specimens the ridge running 

 from the umbo to the apex is very distinct. In all the peduncle is extremely short. 

 Those of Station 192, with a capitulum of almost 10 mm., had apeduncle of 3 mm. at the 

 utmost ; the larger specimens of Raine Island (capitulum 20 to 23 mm.) have a peduncle 

 of 7 to 9 mm. The peduncle of the former specimens is very deeply embedded in the 

 surface of the branch to which they were found attached. This is also the case with the 

 short peduncle of the full-grown specimens from the north of New Guinea. The speci- 

 mens of Raine Island are those of which I have already said above (p. 38) that they were 



