26 



79. nigro-pimctata, Sow. 



80. nimbosa, Lin. 



81. nodosa, Born. 



82. obscura, Sow. 



83. obtusa, id. 



84. octagona, Reeve. 



85. olivacea, Gray. 



86. oriens, Soto. 



87. ostrina, Reeve. 



88. Panamensis, Sow. 



89. Peruviana, Zffra. 



90. Pbilippiana, Reeve. 



91. pica, £070 . 



92. picta, Gmel. 



93. Pileopsoides, Reeve. 



94. pulcbra, *S'o?p. 



95. pustula, Lin. 



96. quadriradiata, Reeve. 



97. reticulata, Dow. 



98. rota, Reeve. 



99. rugosa, £o?<?. 



100. Kupellii, id. 



101. sagittata, Reeve. 



102. salebrosa, zV7. 



103. scutella, Gray. 



104. Sieboldii, Reeve. 



105. Singaporensis, it/. 



106. stellata, it/. 



107. sufrusa, id. 



108. tegula, id. 



109. Ticaonica, it/. 



110. venusta, id. 



111. viminea, it/. 



112. virescens, Sow. 



113. viridula, Lam. 



114. volcano, Reeve. 



Figures. 



Fissurella maxima. PI. /. Fig. 1. Shell, with animal, showing the 

 warts and papillse of the basal disc or foot, and fringed border of the 

 margin extending over the shell's edge. — From the ' Voyage de l' As- 

 trolabe.' 



Fissurella (Fissurellidea) megatrema. PI. /. Fig. 2. Animal of 

 very enlarged proportions, with the shell of small size imbedded in 

 the mantle. — From the ' Voyage dans VAmer. Merid.' 



Fissurella Bridgesii. PI. 24. Fig. 145. Shell, showing from the in- 

 terior its dish-like form and key-hole orifice. 



Genus 2. EMARGINULA. 



Animal ; tvith a short muzzle, terminating a tumid head bearing 

 two subulate tentacles, with subpeduncidated eyes at their exter- 

 nal bases ; a range of cirrhi around the sides at the base of the 

 foot ; mantle simple-edged : anal siphon with its angulated 

 membranous sides projecting from the edges of the fissure ; 

 branchial plumes two. (Forbes.) 



Shell ; conical or depressly conical, rayed or latticed without ; 

 vertex incurved posteriorly ; front side or margin fissured. 



Under this head may be included all the fissured Limpets not referable 

 to the preceding genus. We have seen that in Fissurella the orifice of 

 the shell is central, and that, in its enlargement, the subspiral nucleus of 

 the vertex becomes absorbed. In Emargimda the incurved vertex is pre- 

 served, and the orifice is at the front basal edge of the shell, and takes the 



