MAZATLAN UNIVALVES 451 
Genus LUNATIA, Gray. 
Proc. Zool. Soc. 1847, p. 149, no. 183.—H. & A. Ad. Gen. 
vol. i. p. 206. Operculum horny ; umbilicus straight. 
572. LUNATIA TENUILIRATA, 7%. S. 
LL. t. tenui, cinered, purpureo tinctd sew nebulosad, tumente ; 
anfr. v. rotundatis, totd superficie tenue spiraliter lirulata ; 
sutura impressd, apice haud planato ; apertura ovali, labio 
tenut ; umbilico aperto, ad basin angulato. 
One perfect young and one broken older shell were all that 
were found of this curious little species, remarkable for its 
thinness and spiral sculpture. The larger specimen is ‘055 
long. ‘The smaller one measures long. °036, long. spir. ‘O01. 
lat. °037, div. 110°. 
Hab.—Mazatlan ; 2 sp. off Spondylus ; L’pool Col. 
Tablet 2052 contains the perfect specimen. 
573. Lunatra ————., sp. ind. (a.) 
Tablet 2053 contains an extremely small specimen, ‘034 
across, globose, with a slight sutural groove, and a very small 
slight umbilicus. 
Hab.—Mazatlan ; 1 sp. off Spondylus ; L’pool Col. 
574. LuNATIA —, sp. ind. (b.) 
Tablet. 2054 contains a perfect young and a broken older 
shell of a white, glossy, globose species, with large straight 
umbilicus. The largest is only ‘054 across. 
Hah—Mazatlan ; 5 sp. in shell washings ; L’pool Col. 
575. Lunatia ———-—, sp. ind. (c.) 
Tablet 2055 contains an imperfect specimen ; glossy, white, 
tinged with brown especially about the apex, which is flatten- 
ed; with very fine strie of growth; and an extremely small 
umbilicus, sightly waved by a very small callosity. Liat. ... 
Hab.—Mazatlan ; 2 sp. off Spondylus ; Z’pool Col. 
