PLATE X. 



Hiemiglossa (For. 1—1 — Ij. 



'il.—Fusus aniiquus,Bvit. Oilontofore narrow, and at least au inch and 

 a lialf lonjj. Median broad, base jjroduced ; three subequal 

 denticles or spines. Lateral, lliree subequal spines, the outer one 

 curved, hook-like, and longer. 



32. — F. gracilis, Scotland. Median small, with three denticles or spines, 

 centre one lonf^. The medians are placed on a narrow muscular 

 band, which gives a ladder-like appearance to it. Lateral, two 

 unequal spines. Odontofores of F. gracilis and F. Islandicus 

 are exactly alike, while that of F. unticiuus agrees with Baccinuni 



, unclatum ; that is, the median is broad, with the margin extended 



on each side in a truncated form. The whole tongue is surrounded 

 by a sheath of muscular fibres. 



33. — Cominella maculosa, New Zealand. Median nearly semicircular, armed 

 with three equal spines; lateral, two unequal spines bent outwards ; 

 terminal one longest. Clearly belonging to Ivassida;. 



34 — Nassa reticulata, Brit., Folkestone. Median crescent ic, crowded with 

 numerous nearly equal spines, central one slii^hlly the longest. 

 Lateral armed with two spines triangular in shape ; the formula 

 of spines 2 — 11—2. The family to which this belongs was 

 founded by Stimpson on an odontological basis, "on account 

 of its arched form and numerous deniicled medians." Macdonald 

 pointed out another characteristic, which distinguishes Nassa from 

 Euccinum — " the absence of smaller denticles or spines between 

 the two principal fangs of the laterals." 



35. — Murex trunculiis, Malta. Median, base produced, armed with fine 

 spines alternately long and short ; lateral a simple spine, slightly 

 curved. 



36. — Purpura limnastoma, Madeira. Median slightly curved, narrow, armed 

 with numerous spines; centre long and acutely pointed ; two sub- 

 dued, an outer one rather longer. Lateral simple, hooked, pro- 

 duced at base. 



37. — Mitra fasca, Madeira. Odontofore narrow, linear series of similar 

 teeth. Median armed with seven spines, centre longest ; laterals 

 numerous, gradually diminishing outwards. 



38. — Ci/mha-olla {Fetus of Gray), Gibraltar. A single row of teeth boldly 

 set on a strong muscular baud, tridentate, and acutely pointed. 



39. — Dendronotus arborescens, Greenland. One of the family -^olidjE. 

 Median subquadrate, reflexed, apical, pyramidal ; laterals nume- 

 rous similar reflexed teeth. Formula of band 10 — 1 — 10. 



40. — ^Eolis papulosa, Aberdeen. Mouth furnished with a horny mandible, 

 divided into two parts, and united above by a ligament. Odonto- 

 fore semicircular, armed with numerous rows of simple spines ; 

 tapers off to the stomach or gizzard. 



41. — Aplasia , Vigo Bay. Forty rows of divergent teeth. Median, 



broad, produced at base, reflexed, tricuspid ; centre cusp prolonged 

 and serrated (not well seen in the drawing). Laterals similar, 

 produced, reflexed, tricuspid, numerous. 



42. — A. hybrida, Torbay. Seventy-two rows of divergent teeth. Median, 

 a truncated cone, much produced at base, reflexed and denticulate; 

 laterals numerous, similar teeth. 



