CALYPTR^DiE. 69 



septo lato fornicato, apice miniito. — This white shell grows 

 sometimes on the outside and sometimes on the inside of 

 rounded shells, and takes a convex or concave form accord- 

 ingly. 



23. EXuviATA, f. 141, 142, Nuttall. — Albida vel nivea 

 linguaeformis depressa, angustissime vel mediocriter elongata ; 

 apice product©, frequenter exfoliato, septo elongato, plus 

 minusve fornicato. — The form first described is that of 

 fig. 142. It dilfers from the other ; but this has been caused 

 by the condition of its growth. 



24. NAVICBLLOIDES, f. 143, Nuttcill. — Alba subrotunda 

 subrugosa concava, solida ; lamina septiformi latissimo mar- 

 gine arcuato, apice laterali. — The prevailing free shape of 

 this white Crepidula is circular, slightly curved, with a 

 decumbent apex. 



25. Lessoni, f. 144, 145, 146, Broderip. — Fulva vel alba, 

 ovata vel subtrigona, laminis concentricis extantibus, sub- 

 distantibus radiatim rubro-lineatis, vel vacuis ornata ; mar- 

 gine squamoso ; septo semicirculari ; apice producto leviter 

 curvo. — The typical reddish-streaked shell cannot be dis- 

 tinguished otherwise than by colour from the white variety 

 named C. fimbriata by Reeve. 



26. SQUAMA, f. 147, 148, Broderip. — Depressa, ovata, 

 epidermide subrugosa induta obscure radiatim lineata ; apice 

 producto, terminali, septo medio arcuato. — Differing from 

 the preceding in the absence of outstanding scaly plates. 



27. Walshii, f. 149, 150, Henncmsen (Reeve). — Irregu- 

 lariter dilatata, curva, alba, frequenter planata ; septo sub- 

 trigono, margine dilatato, partim excavato, ad latus obsolete 

 inflecto et plicate; apice parvo, acuto, curvo. — Our f. 150 

 represents the familiar form of C. Walshii, Herm. ; plana, Ad. 

 and Rve. It has been developed on a flat or even concave 

 surface, while the more irregular f. 149 {scabies. Eve.) has 

 had its growth among crudities, and is, therefore, rough and 

 irregular. 



28. CHiNENSis, f. 152, 153, Gray. — Test. jun. rotunda 

 calyciformis paucispiralis ; postea irregulariter expansa ; 

 spira decumbent! ; septo trigone, latere columellari reflexo, 

 tubiformi. — In this species the columellar part of the septum 



