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Show 114 'LIGHTNING'AND'PORCUPINE' MOLLUSCA. [Mar. 6, typified by T. gemmulatus of Philippi1. The peculiar apex may be compared to the stiliform process of Lanthina and Stilifer: and there are several other genera, such as Cacum and Turritella, in which the embryonic spire, which had become useless for the occupancy of the mollusk, is decollated or plugged up. The present genus is allied to Fossarus. IPHITUS TUBERATUS2, Jeffreys. (Plate XX. fig. 12.) S H E L L forming a short cone, solid, opaque, of a dull hue: sculpture, spiral ridges covered with numerous minute tubercles or beads ; there are four or five of these ridges on the last whorl, three on the penultimate, and two on the preceding whorl; the base is also encircled by fine spiral striae ; the stiliform process had been broken off, but sufficient remains to show that it was closely striated lengthwise, as in the fossil species which I have noticed: colour white with a faint tinge of yellow: spire rather short: whorls 3, besides the stiliform process; the last or body-whorl is three or four times the size of all the others put together; the point of the stiliform or cylindrical process in the fossil shell is slightly twisted and blunt: suture deep : mouth rounded, angulated above: outer lip sharp, scalloped by the spiral ridges, expanded and reflected at tbe base of the piliar ; inner lip wanting or inconspicuous : umbilicus none: operculum yellowish- brown, having four or five volutions, the innermost being very small; these are crossed by curved and numerous striae in the line of growth, as in species of Littorina. L. 0*075, B. 0*05. 'Porcupine' Exp. 1870: Atl. St. 6. A single but living specimen. SUMMARY OF THE FOREGOING LIST. Families. Genera. No. of species. VI. SCISSURELLID^E .... SCISSURELLA 3 VII. TROCHID^) MOLLERIA 2 CYCLOSTREMA 13 THARSIS 1 GANESA 2 CIRCULUS 1 TROCHUS 32 OLIVIA 1 VIII. TURBINID^E TURBO 2 PHASIANELLA 1 IX. LITTORINID^l LACUNA 3 CITHNA 5 LITTORINA 3 IPHITUS 1 Total 70 1 The same name (Gemmula) was also proposed by "Weinkauff to distinguish a group or section of tbe genus Pleurotoma. Covered with tubercles. |