MONOGRAPH OF THE GENUS 



HARPA. 



Char. Gen. Molluscum gasteropodum, testa subcanalifer&,ventri- 

 cosa, ovali, costis longitudinalibus reflexis ])lus uiinusve regularibus 

 superne angulatis et acuminatis ornata ; columella et spirre parte 

 encaustis ; spira brevi, coronata, apice mammillata ; apertura 

 magna, autice einarginata, labio externo reflexo, labio interno 

 tenuiter expanso ; columella planulata, autice acuta, plica, cana- 

 lifera costata ad dorsum reflexa. 



The peculiar form and reflected ribs of the Harps distinguish 

 them from the shells of every other genus. In early stages of 

 growth the shells are striated, but the strire become obliterated 

 with age. 



Species. 



1. H. costata, Linn., f. 4, 5, 23. — IT. inflata, rosea, super 

 costas albo-fasciata, inter costas longitudiualiter striata, fusco 

 sparsim picta ; costis crebris, supeme vix trilobatis, ad angulnm 

 acute productis, tunc depressis, ad spiram in culmine plicato ele- 

 vatis ; apertura lata, flavida, labio interno iucrassato, prope me- 

 dium castaneo maculate — Linnaeus having described a species 

 resembling the " Buec'mum Harpa," but with crowded ribs, I 

 agree with the author of ' Ipsa Limisei Conchylia ' that we may 

 conclude this shell, usually known as //. imperialis, to be the one 

 intended. 



2. H. ventricosa, Lamk., f. 18-22, 25. — H. testa inflata, 

 subquadrata, inter costas longitudinaliter striata, strigis undulatis 

 acutis castaneis laqueata ; costis extantibus, fusco et albo fasciatis, 

 superne angulatis, plerumque late reflexis, prope angulum subtri- 

 lobatis, acute carinatis ; spira anfractibus nigro encaustis ; apertura 

 magna, superne subquadrata ; labio interno supra, medio et infra 

 fusco-nigrescente maculato. — This common but beautiful species 

 is distinguished from others by a certain squareness of outline in 



vol. m. u 



