80' 



5. i^r\ LIS X, Fleming ; Gray, Beechey Voy. =.Sty\ifer, Brod. 



/* M^ , 1. ^- , n- s., Adams, MSS. 1. 12(5 o. f. 3. 



^i'ju^ ' •' -'• S. , n. s., Adams, MSS. t. lL>(i. f- 3. . , .. , / . 



ram. 27. Acteomda, p. 160. 



/ Teeth, central none, lateral numerous, uniform, in a diverging rross 

 / series. Operculum horny, spiral, few-whorled. Shell external. 



I 1. AcTEON, n.292. 

 ^ \l. A. Tornatilis. Tornatella fasciata, P/u7/yjpi, t. 128. f. 5. 



> { Tylodina, according to Loven, is allied to this family. 



\tiAffmM/t l^JU/tP^t***^'^^^- Operculum annular. j. Eyes far behind tentacula. 



Fam. 28. Rissoellidfe. 



. Front of head nicked, lohes elongate cylindrical, nearly as long as 



O^r^lA*-^ ""T//*^ ) the tentacula. Eyes far back. Operculum half-ovate, annular ; nu- 

 '^ 2 / ^ Jij-*i I cleus near the inner straight edge, with a central internal process. 



^ 1. RissoELLA, Gray, 1848, n. 2'^'^,part. 



1. R. glaher. Rissoa? g., ^Wer, t. 125. f. 3. , 



1^. ^'^Order II. Scutibranchiata. 



.t ^x-'^ll consisting of two series of lamellfc, forming one or tuo scne*« ^"wX 

 4/iaL- u4/^i^^^ I over the back of the neck or on the mider edge of the mantle round 

 3r»*i^*t-^^'^ ^ ^^^ ^""*- Animal hermajihrodite, self-imi)regnating ? Shell spiral 

 or symmetrical, conical. Rectum often traversing the heart. 



This order may be thus divided : — 



Normal. Heart traversed l)y the rectum ; lateral teeth very nu- 

 merous. Scuitibranches, Cuvier, Trochina, Loven. Containing the 

 first seven families. 



Abnormal. Heart separate from the rectum. Teeth moderate 

 in number, in pairs. Containing the remaining families. 



iJ ' J ■\ ^j-i^a ^nr7tyf^ Sect. 1. Podopbthabiia, \^. '[AS. 



llyes pedicelled, separate from the tentacula. Shell and oper- 

 fX_L,juJJiA*^v^i^*-'~ Ipulum spiral. Teeth numerous, lateral ones uniforrn, very numerous, 

 A)IjC^^ Jcroit't/ef/. 



A. Sides of the foot with a continued fringe, with three or four elon- 

 . .. (jiAied tentacula on its upper surface. Shell internally pearly. 



t^^TM^ »-wn>M C^Lt^^rtO^y/ Fam. 1. Turbinida, p. 143. 



''****^'*^'*^ Al. i -//Operculum hornv, with a solid, convex, calcareous coat. Frontal 

 ,ot,,-^^^„/UrM^Ay\ '»^/|,|n.,„i;,j,es two, l)clow the tentacula, lobed. 



a. Turbina. Mouth and oper. subcircular. 



^^/ y * Oper. vnthout spiral ridges. 



1. Sarmatuus. Oper. externally covered with nuiucious sepa- 



