62 MOLLUSCA OF THE 'lightning' ETC. EXPEDITIONS. [Jan. 20, 



Havino- myself seen this remarkable species dredged off Martha's 

 Vineyard on the New-Englaud 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. iii. 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-hke 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 1 6 

 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 strise. It is figured in Plate VI. fig. 10 for future 

 identification, and may be called bizonalis or bizonale. 



Summary of the foregoing Mollusca. 

 Families. Genera. No. of species. 



XIX. IANTHINID.E Ianthina 2 



XX. NATICID^ Natica 21 



XXI. NERITIDvE Neritina 1 



XXII. SOLARIID^E Solarium .... 4 



Adeorbis 4 



Fossarus 1 



Seguenzia 6 



XXIII. XENOPHORIDiE .... Xenophora 1 



XXIV. VELUTINID.^ Lamellaria 2 



XXV. CAPULID^ C.4PULUS 1 



XXVI. CANCELLARIIDtE Torellia 2 



Trichotropis .... 3 



Cancellaria .... 4 



XXVII. APORRHAIDiE Aporrhais 2 



XXVIII. CERITHIID^ Stilus I 



l.eocochlis i 



Cerithium 10 



XXIX. CERITHIOPSID^ .... Triforis 2 



Cerithiopsis .... 7 



Total 75 



EXPLANATION' OF THE PLATES. 

 Plate IV. 



Fig. 1, la. Natica notahilis, p. 31. 



2, 2a. subplicata, p. 32. 



3, angulata, p. 32. 



4, 4a. glohosa, p. 33. 



5, 5a. compacta, p. 33. 



Fig. 6, 6a. Natica obtusa, p. 33. 



7, 7a. operculata, p 34. 



8, 8a. Adeorbis dejyressus, p. 41. 

 ■y. Fossarus reticulatus, p. 41. 



