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Show 364 DR. GWYN JEFFREYS ON THE MOLLUSCA OF THE [May 20, the late Mr. Arthur Adams and my friend Captain St. John, and I cannot detect the slightest difference between any of them in shape, coloured band, umbilicus, or dentition of the pillar. P. laviuscula of the Crag has no umbilical perforation; otherwise the recent and fossil species are exactly similar. Some of the recent as well as Crag specimens, and those of P. plicosa (if this be not the same as the Crag species) have the throat or inside of the outer lip thickened and crenated, as in Odostomia conoidea and other species of that genus. It must be borne in mind that species of different genera are common to the North Atlantic and North Pacific Oceans, as well as to the Crag, e. g. Pecchiolia acuticostata. MATHILDA OUADRICARINATA, Broechi. Turbo quadricarinatus, Brc. Conch. Foss. Subap. ii. p. 375, t. vii. f. 6. M. quadricarinata, Kobelt in Jahrb. d. d. Mai. Ges. 1874, p. 226, t. ii. f. 2, 2a. ' Porcupine' Exp. 1870 : Atl. St. off C. Sagres, 26-30, 36 ; Med. 50, 50a, Benzert Road, Rasel Amoush, Adventure Bank. Distribution. Bay of Biscay ('Travailleur' Exp. 1881), Mediterranean and Adriatic, Madeira (Watson) I; 8-227 fms. Fossil. Miocene: Maine et Loire (Baudin), Malaga (Duncan). Pliocene : Antwerp Crag (Omalius), Biot, and Italy. A Sicilian specimen, kindly sent me by the late Professor Aradus, measures nearly an inch and a quarter in length and y7^ cf an inch in breadth. The sculpture of this species varies considerably, and this has, of course, given rise to several synonyms, including Eglisia macandrea of A. Adams, and two or three so-called species of Brugnone. The correct position of the genus Mathilda, O. Semper, 1865, is rather questionable. It certainly approaches Turritella in some respects ; and my only reason for placing it provisionally in the Pyramidellida is the heterostrophe or sinistrorsally spiral apex. I have thought it desirable to give (Plate XXVII. fig. 9) a magnified figure of this character. I subjoin a description of the animal taken from a living specimen during the ' Porcupine ' Expedition of 1870 :-Body cream-colour : tentacles thread-shaped, smooth, very long and slender, bluntly pointed, and diverging: eyes proportionally large, seated on small tubercles or bulbs on the outer side of the tentacles about one fourth from their base : foot large, in front deeply bilobed with remarkably long auricles, behind angulated on the upper part and rounded at the tail or extremity ; the foot-lobes are jagged inside, and double-edged in that part with a row of close-set short and exquisitely fine cilia which are in continual motion : operculum chitinous, rather solid, multispiral with umbilicated whorls, like that of Turritella terebra. Animal active and bold. |
