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Show 62 M O L L U S C A O F T H E ' L I G H T N I N G ' E T C . E X P E D I T I O N S . [Jan. 20, Having myself seen this remarkable species dredged off Martha's Vineyard on the New-England coast, and carefully compared it with the Mediterranean and fossil species, I cannot find the slightest difference between any of the specimens. It is the Cerithium terebrale of C. B. Adams, Bost. Journ. N . H. hi. pi. 3. f. 7 (1841). The occurrence of this European species not merely on the coasts of North America but also in the Miocene formation of both countries is remarkable. The last whorl has a basal ridge or keel, besides a thread-like line below it and encircling the pillar. The apex consists of two or three smooth and glossy whorls ending in a globular point. There is the same very short canal as in Cerithiopsis ; but the pillar is longer, more flexuous, and recurved at its base as in the typical species of Cerithium. I have a fragment of a Cerithiopsis or Cerithium from Station 16 of the 'Porcupine' Expedition of 1870, which is worthy of notice. Each whorl has curved longitudinal ribs, which are crossed by two thread-like spiral striae. It is figured in Plate VI. fig. 10 for future identification, and may be called bizonalis or bizonale. SUMMARY OP THE FOREGOING MOLLUSCA. Families. Genera. No. of species. XIX. IANTHINID.E IANTHINA 2 XX. NAITCID^E NATICA 21 XXI. NERITIDyE NERITINA 1 XXII. SOLARIIDiE SOLARIUM 4 ADEORBIS 4 FOSSARUS 1 SEGUENZIA 6 XXIII. XENOPHORIDiE .... XENOPHORA 1 XXIV. VELUTINID.E...... LAMELLARIA .... 2 XXV. CAPULIDiE CAPULUS 1 XXVI. CANCELLARIIDJE.. .. TORELLIA 2 TRICHOTROPIS .... 3 CANCELLARIA .... 4 XXVII. APORRHAID.E APORRHAIS 2 XXVIII. CERITHIID^l STILUS 1 L^OCOCHLIS 1 CERITHIUM ...... 10 XXIX. CERITHIOPSID^E .... TRIFORIS 2 CERITHIOPSIS .... 7 Total. 75 EXPLANATION OF THE PLATES. PLATE IV. Fig. 1, la. Natica notabilis, p. 31. 2, 2a. subplicata, p, 32. 3. angulata, p. 32. 4, 4a. globosa, p. 33. 5, 5a. compacta, p. 33. Fig. 6, 6«. Natica obtusa, p. 33. 7, 7a. operculata, p 34. 8, 8a. Adeorbis depressus, p. 41. 9. Fossarus reticidatus, p. 41. |
