GASTEEOrODA. 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. Eed Sea, Philippines, Pacific, Panama. 

 (Cuming. ) 



AcM^A, Eschscholt25. 



Etymology, acme, a 



Synoyiyms, Tectura, M. Edw. Lottia and Scurria, Gray. 

 Patelloida, Quoy. 



Type, A. testudinalis. PI. XL, Fig. 24. 



Shell like patella. Animal with a single pectinated gill ; 

 lodged in a cervical cavity, 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 

 caeca, Miiller. 



Shell WiixiMte, SL]^ex. posterior. Animal hlind. , Britam. 30—90 

 fathoms. 



Pilidium, Forbes. P. fulva, Miiller. Britain. 20 — 80 fathoms 

 water. 



Shell small, apex anterior. Animal blind; gills 2, not 

 projecting; mantle even-edged. Both lepeta and pilidium 

 have large single median teeth, with trilobed hooks ; and 2 

 hooked uncini on each side. 



Gadinia (Adanson), Gray. 



Type, G. peruviana. PI. XL, 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 cervical gill; tentacles expanded, 

 funnel-shaped. 



Distribution, 8 species. Mediterranean, Eed Sea, Africa, Peni. 



Fossil, 1 species. Sicily. 



SiPHONARiA, Sowerby. 



Ty2)e, S. sipho. PI. XL, Fig. 25. 



Shell like patella; apex sub-central, posterior; muscular 

 impression horse -shoe shaped, divided on the right side by a 



