GASTEROrODA. 281 



tinued in front of the head. Found on the fronds and stalks of 

 sea-weeds. Britain, Cape, CajDe Horn. 



Scutellina, Gray. S. crenulata. Shell with a broad margin 

 internally. 7 species. Eed Sea, Philippines, Pacific, Panama. 

 (Cnming.) 



AcM^A, Eschscholtz. 



etymology, acme, a 



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

 Patelloida, Quoy, 



Type, A. testudinalis. PI. 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. Le^eta, Gray (= pro-pilidium, Forbes). Patella 

 caeca, Miiller. 



/S/ieZ? minute, apex pos^enor. ^mma? blind. Britain. 30 — 90 

 fathoms. 



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

 water. 



Sliell 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, Bed Sea, Africa, Peru. 



Fossil, 1 species. Sicily. 



SiPHO]S"AiiiA, Sowerby. 



Ttjpe, S. sipho. PL XL, Fig. 25. 



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

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



