SCURRIA-LOTTIA. 65 



bounded inside by a greenish line ; ordinarily tessellated with 

 brown and white, sometimes with green or yellow ; not unfre(juently 

 with very slight markings of white, or none at all, in Avhich case the 

 color is either dark-greenish-brown, (P. striata Rve.,) or with inter- 

 mediate stages to very light-greenish-white. (Opr.) 



Length 34, breadth 28, alt. 8 mill. 



Central America to Gulf of California. 



Acmcea mesoleuca IMke., Zeitschr. f. Mai. 1851, p. 38. — Cpr. Maz. 

 Cat., p. 203. — A. mutahilis (part) Mke. I. c, p. 37. — P. diaphana Rv., 

 Conch. Icon., f. 61.—Lottia patina f C. B. Ad., Pan. Cat,, p. 241.— 

 Lottia pintadina (part) Gld., Exped. Sh., p. 9. — P. striata Rve., 

 Conch. Icon. f. 99. — P. vespertina Rv. I. c. f. 67. — Scurria mesoleuca 

 Dale, Amer. Journ. Conch, vi, p. 264, t. 15, f. 19 (dentition). 



This variable species has much in common with Acmcea patina; 

 that species, however, is not green inside. Specimens from the 

 Galapagos Is., are nearly typical. They have been described by 

 Reeve as Patella striata, (not P. striata Quoy). See PI. 8, figs. 100, 1. 



The P. vespertina of Reeve (PI. 8, figs. 98, 99) is doubtless 

 synonymous. 



Subgenus Lottia (Gray) Carpenter, 



Lottia (Gray mss.), Sowb., Genera of Shells, pi. 42, fig. 1. — 

 Carpenter, Journ. de Conch. 1865, p. 140. — Am. Journ. Conch, 

 ii, p. 342, 1866. — Dale, Amer, Journ. Conch, vi, p. 260. — Tectnrella 

 Cpr., Smiths. Check List W. C. Sh., p. 3, Um.~Tecturina Cpr., 

 Smiths. Rep. 1860, p. 219. — Lecania Cpr. mss., see Amer. Journ. 

 Conch, ii, p. 343. 



The branchial cordon is interrupted over the head. Animal 

 otherwise as in Scurria. Dentition, pi. 38, fig. 3. 



S. gigantea Gray. Plate 38. 



Shell large, solid, oval, depressed, the apex near the front margin; 

 outer surface eroded, of a spongy texture, dull brown, gray toward 

 the summit. Inside having a black rim around the margin, deep 

 chestnut brown outside of the muscle-impression, which is strong, 

 bluish or purplish-white. Central area chestnut brown, more or less 

 mottled with white, rarely entirely white. 



Length 75, breadth 55-60, alt, 17-20 mill, 



San Francisco, Cal., to Panama. 



