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Show 370 MR. W. F. LANCHESTER ON TI1E [Dec. 2, ]>. amaryllis, amphitrite, improvisus), I have been content to follow him in this respect, and to consider No. II. as a colour - variety of No. I., the latter being then necessarily regarded as a subspecies of B. amaryllis. For my justification in separating this form from B. amaryllis, I must refer to the differences about to be described. No. I. =the subspecies. This form agrees with B. amaryllis in all characteristics, whether in structure of shell or structure of body, except those of the opercular valves. These latter, although agreeing in general shape with those of B amaryllis, present the following differences:- (a) The scutum.-Articular ridge prominent, with a very slight tendency to be reflexed to the tergal margin (this is better seen in the large specimens of the subspecies than in the smaller specimens of the variety); adductor crest prominent. These differences have been already noted by Dr. Weltner in his useful Catalogue of recent Cirripede species (I. c. supra). (b) The tergum.-Depressor crests well developed; spur, only half its own width from the basiscutal angle. I think there is no doubt that, apart from No. II., these differences would entitle No. I. to be considered as a variety of the species, and as such I should have classed it, did I not, as I have said, follow Darwin in considering colour difference of varietal worth, so that these differences must be considered as subspecific. No. II. = var. clarovittata. Presents the same structural distinctions as the subspecies, and differs in the shell being white with rather closely placed longitudinal hyaline lines. In one specimen of this variety the basal margin of the tergum is very concave between the spur and the basicarinal angle, while the basiscutal angle is sharp, almost tooth-like; and the basal margin of the scutum presents a broad, shallow notch not far from its basi-occludent angle. The large specimens are about 1| in. in greatest diameter of base, and about l j in. high ; the small barely | in. across the base, and § in. high. 2 3. B a la n u s .eneas, sp. nov. (Plate XNXIV. figs. 4 -4 b.) Loc.------ ? Shell white, smooth, not very tall, internally longitudinally ribbed ; orifice toothed, but not deeply, large and rhomboidal. Radii reduced and very narrow; basis porous, parietes solid. Scutum with the lines of growth distant, not prominent; articular ridge prominent, extending about halfway down the tergal margin; adductor ridge not prominent. Tergum broad, without any beak ; spur short, a quarter of the width of the whole basal margin, placed about two-thirds of its own width from the basiscutal angle, its apex rounded. |