Terrestrial molluscs of Pemba Island, Zanzibar, Tanzania, and its status as an " oceanic " island Author Rowson, B Author Warren, B. H. Author Ngereza, C. F. text ZooKeys 2010 70 1 39 http://dx.doi.org/10.3897/zookeys.70.762 journal article http://dx.doi.org/10.3897/zookeys.70.762 1313-2970-70-1 19. Opeas delicatum Taylor, 1877 Opeas delicatum Taylor 1877b : 281-282; pl. III, fig. 3 Notes. Pemba specimens reach 7.0 x 2.5 mm, being much smaller and narrower than Opeas lamoense . Griffiths and Florens (2006) figure specimens referred to Allopeas clavulinum (Poitiez & Michaud, 1838) and Allopeas mauritianum (L. Pfeiffer, 1847) that they suggest were introduced to the Mascarenes from East Africa. Both resemble some specimens of Opeas delicatum . Verdcourt was familiar with Allopeas clavulinum in botanic gardens in the UK, which in turn have been said to come from East Africa ( Kerney and Cameron 1979 ) yet never included Allopeas clavulinum in his East African lists ( Verdcourt 1983 , 2000 , 2006 ). This should be further investigated.