122 GASTEROPODA. PURPURADS. 
Synopsis Generum. 
* Teste Siphon brevissimus. Peritrema posticé planiusculum. 
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Apertura ad dextram et ad sinistram acumi- 
Maia. «SIPHOR TECUTVOS  .. oie chi oe 59. Purpura. 
Apertura ad dextram acuminata, posticé si- 
nuata. Siphon ad sinistram curvatus.. 60. Hima. 
** Teste Siphon mediocris aut longissimus. Peritrema pos- 
ticé conforme. 
Siphon mediocris, recurvus, ad apicem peri- 
tremate tectus ....-..435.,.52.%s. 8-2. « Ol See 
Siphon elongatus aut longissimus, rectus, ad 
apicem peritremate nullo instructus.... 62, Fusus. 
*** Teste Siphon brevis. Peritrema postice conforme. 
Apertura ad dextram emarginata........ 63. MANGELIA. 
Apertura ad dextram perfecta .......... . 64. Bena. 
Genus 59. Purpura. 
Purpura, Bruguiere, Cuvier. 
Testa subovata, acuté spiralis. Apertura ad dextram et ad 
sinistram acuminata. Siphon brevissimus, recurvus. Peri- 
trema anticé interné marginatum, crenulatum, posticé fortiter 
inchoatum, planiusculum. Tentacula ultra medium externé 
dilatata, oculigera. Oculi plano-convexi. 
Shell rather ovate, acutely spiral. Aperture acuminated on 
the right and left side. Siphon very short and recurved. Pe- 
ritreme anteriorly internally margined and wrinkled; behind 
strongly commenced, and flattish. Tentacula dilated externally 
beyond their middle; the dilated portion bearing the eyes, 
which are plano-convex. 
1. Purpura LAPILLUS. 
P. anfractibus mediocriter convexis, longitudinaliter elevato- 
