B. humilis. Conrad, in the ‘American Journal of Science,’ vol. ii (N. S.), p. 400, 1846, has given a short description, with a woodcut, of this species, from the upper Eocene of Florida. The opercular valves are not described, and I doubt whether the species could be recognised.
2. Family—VERRUCIDÆ.
Cirripedia without a peduncle: scuta and terga, not furnished with depressor muscles, moveable only on one side, on the other side united immoveably with the rostrum and carina into an asymmetrical shell.
The one genus herein contained differs so considerably from all the others in the Order, in the extraordinary unequal development of the two sides of the shell, that I have instituted a Family for its reception. If compelled to place it in one of the foregoing families, I should with much hesitation rank it in the [sub-family Chthamalinæ], rather than amongst the Lepadidæ; for it is destitute of a peduncle, and has a shell, though a very different one from that of any true sessile cirripede. In the interfolding sutures which may be considered as representing radii or alæ, in the basis being divided into concentric slips, and in the whole of the basis being attached to the supporting object, this same line of affinity is clearly manifested. On the other hand, in the general shape, manner of growth, and kind of articulation of the scutum and tergum, there is so close an approach to the Lepadidæ, that had I seen these very important valves separately, I should certainly have concluded that they had come from a Pollicipes, allied to certain Cretacean fossil species, as P. fallax and elegans; it likewise, perhaps, deserves notice, that the upward growth of the rostrum, in [Verruca nexa], is a peculiarity found only in the valves of the Lepadidæ. [Verruca] differs both from the Lepadidæ and [Balanidæ] in the whole shell or external covering, having no other muscle besides the adductor scutorum. In the characters derived from the animal’s body, [Verruca] approaches both families; but in the absence of branchiæ, and in the great development of the caudal appendages, perhaps it comes rather the nearest to the Lepadidæ. Whatever affinity there is to the [Balanidæ], it is much stronger to the sub-family [Chthamalinæ] than to the [Balaninæ]; though the non-bullate labrum, in three of the species, and the great dissimilarity of the third cirrus from the three posterior pairs, at first seems to indicate a closer relationship to the [Balaninæ]; but the labrum is never notched, as in the latter sub-family, and in [V. nexa] it is bullate, and supports palpi of only small size. The dissimilarity, also, of the third pair of cirri, compared with the posterior pairs, is hardly greater than in [Chthamalus intertextus] and [Chamæsipho columna], members of the [Chthamalinæ], though abnormal in this one respect. Perhaps even a special affinity is evinced between certain species of [Chthamalus], as [C. intertextus], and certain species of [Verruca], as [V. nexa], namely, in the interfolding sutures and in the very peculiar, inflected basal margin of the walls. Upon the whole, the affinities of the [Verrucidæ] are complex, and nearly equally divided between the two great families of [Balanidæ] and Lepadidæ, or sessile and pedunculated cirripedes.
Genus—VERRUCA. Pl. [21.]
VERRUCA.[136] Schumacher. Essai d’un Nouveau Syst. Class., 1817.
CLYSIA. Leach. Journal de Physique, tom. 85, July, 1817; Clisia, Leach, Encyclop. Brit. Suppl., vol. 3, 1824; Clitia, G. B. Sowerby, Genera of Recent and Fossil Shells.