MAZATLAN UNIVALVES 451 



GENUS LUNATIA, Gray. 



Proc. Zool. Soc. 1847, p. 149, no. 183. H. fy A. Ad. Gen. 

 vol. i. p. 206. Operculum horny ; umbilicus straight. 



572. LUNATIA TENUILIRATA, n. S. 



L. t. tenui, cinered, purpureo tinctd seu nebulosd, tumente ; 

 anfr. v. rotundatis, totd superficie tenue spiraliter lirulatd ; 

 suturd impress d, apice haud planato ; aperturd ovali, labio 

 tenui ; 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. '01. 

 lat. '037, div. 110. 

 Hob. Mazatlan ; 2 sp. off Spondylus ; IS pool Col. 



Tablet 2052 contains the perfect specimen. 



573. LUNATIA , sp. ind. (a.) 



Tablet 2053 contains an extremely small specimen, '034 

 across, globose, with a slight sutural groove, and a very small 

 slight umbilicus. 

 Sab. 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. 

 Hab. Mazatlau ; 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 striae of growth ; and an extremely small 

 umbilicus, slightly waved by a very small callosity. Lat. 

 Hab. Mazatlan ; 2 sp. off Spondylus j L'pool CoL 



