84 FOSSIL CIRRIPEDIA. 
latera. The consequence of this arrangement is, that in the alternate whorls there are 
in one, four of the large lateral scales and none of the smaller end scales; and in the 
whorl, both above and below, only two of these large lateral scales, and four of the carinal 
and rostral scales; so that the alternate whorls (fig. 4) had an unequal number of scales, 
namely, four and six. 
Growth.—New scales for the peduncle are formed round its upper edge, at the bases 
of the valves of the capitulum, the chief growth of which, as we have seen, is downwards : 
hence, we here have, as in other pedunculated Cirripedia, a principal line of growth round 
the summit of the peduncle. It can be seen that a new scale is first formed under the 
second latus, at the carinal end of the peduncle ; and this agrees with the fact that there 
is one more scale in this row than in that next to it; and one more in the latter, than in 
the row under the scutum. I may mention, as in conformity with this fact, that in the 
development of the young of Scalpellum vulgare from the larval condition, the calcareous 
scales on the peduncle first appear under the carina. 
Attachment.—With respect to the attachment, Mr. G. B. Sowerby seems to have felt 
great difficulty on account of the peduncle ending in so fine a point; but the peduncle 
of Scalpellum vulgare, when carefully dissected from the coralline to which it is attached, 
often ends in a much finer point, and is symmetrically attached to the branch by its 
narrow rostral margin. In Loricula, the attachment was probably by one lateral face of 
the lower part of the peduncle; for it is by no means unusual for the cement-stuff (even 
when proceeding only from the two original central orifices, where the prehensile antennze 
of the larva may still be found) to encroach largely on the peduncle, and thus fix it down. 
The calcareous scales of Pollicipes, and the horny spines of Ibla, may often be found thus 
embedded and firmly fixed to the supporting rock ; it is moreover possible, that in Loricula 
the cement was poured out of orifices, specially situated on one side of the peduncle, as 
takes place along the rostral margin in Scalpellum vulgare, and high up on both sides of 
the peduncle in Lepas fascicularis. 
Dimensions.—Entire length of the specimen rather above one inch: width of widest 
part of the peduncle °6 of an inch. 
On the probable condition of the Specimen when perfect.—I have already remarked 
that the three valves of the capitulum, and the five rows of scales on the peduncle, must 
have had an opposite series. I at first thought it extremely improbable that the animal 
should have been split so exactly down the middle ; and I conceive, in most genera, as in the 
common Lepas, it would be quite impossible to effect this; but in removing the terga and 
scuta from one side of several specimens in Ibla and Lithotrya, it was difficult to prevent 
exactly half of the membrane of the peduncle (which in these genera is thin) being torn 
off with them. Mr. G. B. Sowerby, jun., also has remarked (Annals of Nat. Hist., 1843, 
p. 261), that, owing to the rostral and carinal rows of small scales not intersecting each 
other, the splitting of the specimen into halves along this plane would be much favoured. 
The inner edge of the so-called second latus could not have touched the inner edge of its 
