GASTEROPODA. 281 
tinued in front of the head. Found on the fronds and stalks of 
sea-weeds. Britain, Cape, Cape Horn. 
Scutellina, Gray. S.crenulata. Shell with a broad margin 
internally. 7 species. Red Sea, Philippines, Pacific, Panama. 
(Cuming.) 
AcmA, Eschscholtz. 
Hiymology, acme, a 
Synonyms, Tectura, M. Edw. lLottia and Scurria, Gray. 
Patelloida, Quoy. 
Type, A. testudinalis. Pl. XI., Fig. 24. 
Shell like patella. Animal with a single pectinated gill; 
lodged in a cervical cayity, and exserted from the right side 
of the neck when the creature walks. Lingual teeth 3 on 
each side of the median line. Low water to 30 fathoms. 
(Forbes. ) 
Distribution, 61 species. Norway, Britain, Australia, Pacific, 
West America. 
Sub-genera. Lepeta, Gray (= pro-pilidium, Forbes). Patella 
ezeca, Miller. 
Shell minute, apex posterior. Animal blind. Britain. 30—90 
fathoms. 
Pilidium, Forbes. P. fulva, Miller. Britain. 20—80 fathoms 
water. 
Shell small, apex anterior. Animal blind; gills 2, not 
projecting; mantle even-edged. Both lepefa and pilidiwm 
haye large single median teeth, with trilobed hooks; and 2 
hooked uncini on each side. 
GADINIA (Adanson), Gray. 
Type, G. peruviana. Pl. XI., Fig. 26. 
Synonym, Mouretia, Sby. 
Shell conical; muscular impression horse-shoe-shaped, the 
right side shortest, terminating at the siphonal groove. 
Animal with a single ceryical gill; tentacles expanded, 
funnel-shaped. 
Distribution, 8 species. Mediterranean, Red Sea, Africa, Peru. 
Fossil, 1 species. Sicily. 
SIPHONARIA, Sowerby. 
Type, 8. sipho. Pl. XI., Fig. 25. 
Shell like patella; apex sub-central, posterior; muscular 
impression horse-shoe shaped, divided on the right side by a 
