SCAPHANDER. 443 



vicarious immortality, by associating the names of their 

 wives with their real or supposed discoveries. Gioenia, 

 as a genus, was adopted by Bruguiere ; Retz substituted 

 for it Tricla. This strange mistake was exposed and 

 rectified by Draparnaud. 



An obsolete synonym of the present genus is Assuta 

 of Schumacher. 



Scaphander ligna'rius*, Linne. 



Bxdla lignaria, Linn. S. N. p. 1184. S. lignarius, F. & H. iii. p. 536, 

 pi. cxiv. p. f. 3, and (animal) pi. VV. f. 5, as S. lignaria. 



Body fleshcolour, orange, browmish-yellow, or creamcolour : 

 mantle folded over the underside of the shell and the lower 

 part of the crown or apex : head shield-like, wedge-shaped and 

 rounded or slightly indented in front : tentacles forming a 

 single squarish lobe, being a continuation of the head ; this 

 lobe has angular or ear-shaped comers on the upper or hinder 

 part: eyes, none perceptible: foot bulky, of an oval shape, 

 squarish, corresponding and coextensive with the head in front, 

 expanded and bluntly notched behind; the side-lobes fre- 

 quently overlap part of the shell : [odontophore, rhachis 

 wanting ; uncini arranged in a single row, claw-shaped, 

 crenellated on the hinder margin towards the point ; outer 

 side winged, with a crest at the base (Loven).] 



Shell pear-shaped, peaked or acuminated at the top, and 

 expanded at the base, rather solid, nearly opaque, and some- 

 what glossy : sculpture, numerous spiral striae or fine grooves, 

 which (owing to the size of the shell) are very conspicuous ; 

 they are equally strong in every part, and are equidistant, 

 except at the top (where they become more or less crowded), 

 and also except an occasional slighter intermediate stria ; the 

 interstices of the spiral stria? or grooves are crossed by fine 

 and close-set longitudinal striae, which often give the former 

 a punctate appearance ; the whole surface is covered with 

 close-set microscopic spiral lines and with equally numerous 

 and minute longitudinal stria?, producing by their intersection 

 a slight cancellation : epidermis orange or tawny, passing 

 into chestnut : colour, under the epidermis, yellowish- white or 



* From its colour resembling that of fir- wood. 



