170 PHYLLOBRANCHIA. TURBONIDE. 
This very elegant shell was kindly communicated to me by 
James Drummond, Esq., Professor of Botany in the Botanical 
Garden, Cork. 
STIRPS IT. 
Genus 74. Trocuvs. 
Trochus Auctorum. 
Testa conica, elata, swper carmam. Apertura transversim 
depressa, marginibus disjunctis. Co/uwmella arcuata. Peri- 
trema tenue. Umbilicus nullus. Operculum corneum. 
Animal ore brevi. Tentaculis quatuor ; duobus superioribus 
brevissimis, subconicis, apice oculigeris; duobus inferioribus 
longissimis, tenuissimis, acuminatis, filamentulis utrinqué in- 
structis. Pallio super pedes lateralitér utrinqué filamentis 
tribus longissimis acuminatis, filamentulis utrinqué instructis. 
Ova pedunculata. Pedunculum ad animalis junioris tenta- 
culorum latera locatum. 
The shell is conic and elevated ; the aperture is transversely 
depressed above its carina; its hinder margins are disjomed ; 
its column arched ; the peritreme thin ; the umbilicus wanting ; 
the operculum horny. 
The animal has a short mouth; four tentacles; the two in- 
ferior ones very short, nearly conic, bear the eyes at their ex- 
tremities ; the two inferior ones are very long, very slender and 
acuminated, with very minute filaments on each side; the man- 
tle above the feet on each side has three very long, acuminated 
filameuts, with very minute filaments on each side. 
The eggs are pedunculated ; the peduncle is situated at the 
sides of the tentacles of the young animal. 
Synopsis Specierum. 
1, papillosus. Testa tenui, fragili ; anfractibus lineis, spiralibus, 
regularibus, tuberculatis, elevatis, sculptis. 
2. Cranchianus. Testa tenui; anfractibus lineis spiralibus, 
distantibus, elevatis, simplicibus sculptis. 
