xii, 
“ORDER OPISTHOBRANCHIATA. 
SUB-ORDER NUDIBRANCHIATA. 
These we do not attempt to classify. 
SUB-ORDER TECTIBRANCHIATA. 
A. CEPHALASPIDEA. 
Actaeonidee. 
Actaeon, Montfort, 1810. 
(type) A. tornatilis, Z. 
Tornatinide. 
Retusa, Brown, 1827, 
(type) R. obtusa, Mont. 
Utriculus, Brown, is antedated by Schumacher, in the Conide. Our 
other British species are truncatula, Brug., nitidula, Lovén, umbilicata, 
Mont., and mammillata, Phil. 
Volvulella, Newton, 1891. 
(example) V. acuminata, Brug. 
Cylichna, Lovén, could not be used for this species, even if it had not 
been preoccupied. Volvula, A.Ad., next on the list, clashes with the 
prior Volvulus, Oken, and therefore the above is used. 
Scaphandride. 
Scaphander, Monéft., 1810. 
(type) S. lignarius, Z. 
Roxania (Leach), Gray, 1847. 
(type) R. utriculus, Brocchi. 
Diaphana, Brown, 1827. 
(type) D. minuta, Brown. 
This is the Bulla utriculus of Turton, which clashes with B. utriculus, 
Gmel., and we have therefore used Brown’s name. Our other species are 
expansa, Jef., ventricosa (= ventrosa), Jeff, and, perhaps, globosa, 
Lovén. 
Bullinella, Newton, 1891. 
B. cylindracea, Penn, 
Amongst the synonyms are Bullina, Risso, non Férussac ; and Cylichna, 
Lovén, non Cylichnus, Burmeister. Another British species is alba, 
Brown. 
