MAZATLAN UNIVALVES 195 



253. LEPIDOPLEURUS CLATHKATUS, n. s. 



L. t. subrotundatd, depressd, (ad angulam ISO^Jfusco-oliva- 

 ced ; valvis latissimis, marginibus lobatis, interstitiis subrectis ; 

 valvis intermediis, injugo et (plus minusve) totd superjicie granu- 

 latis; costis duabus, tubcrculispravalidismunitis, und diagonali, 

 allerd supra marginem decurrente ; areis lateralibus parvis, 

 granulatis ; areis centralibus clatkris iv. utroque in latere 

 longitudinalibus munitis, clatkris tuberculatis, interstitiis gran- 

 ulatis ; valvd anticd costibus radiantibus circiter xi. rotundatis, 

 subtuberculatis ; limbo pallii latissimo, squamulis minimis, 

 mollibus, conferto ; marginibiis valvarum simplicibus, antico 

 fissuris ix. ad costas Jiaud convenientibus, testa externd, quasi 

 subgrundd, circumeunte. 



One very small specimen was discovered on a stone to which 

 a OiTLcibulum had been attached, beautifully perfect except in 

 the loss of the anterior valve. A dead anterior valve was found 

 of a much larger specimen, displaying a marginal structure like 

 that of L. sanguineus. The shell is remarkable for the strong 

 bars across the ventral areas, and the stout rows of tubercles 

 which run, the one diagonally, the other along the interstitial 

 margin. The mantle is very broad, and crowded with minute 

 scales. Long. *17, lat. '12, alt. '02. 

 Hob. Mazatlan ; under stones, extremely rare ; L'pool Col. 



Tablet 901 contains the specimen. 



254. LEPIDOPLEUEUS BULLATTJS, n. s. 



L. t. subovatd, elevatd (ad angulam 110V olivaced ; valvis 

 intermediis lineis diagonalibus bullis extantibus ornatis ; areis 

 lateralibus angustissimis, tuberculatis, inter 'dum bullis munitis ; 

 areis centralibus lineis tubercularum, in utrdque parle circiter 

 vii., lineis diagonalibus perpendicidaribus : interstitiis ubique 

 granulatis ; valvis terminalibus lineis bullarum radiantibus 

 circiter xi., mucrone subconspicuo ; limbo pallii lato, pilulis 

 minimis instructo ; valvarum lobis biangulatis, sinu alto ; 

 marginibus valvarum simplicibus., in valvis intermediis Jissurd 

 uno, terminalibus circiter vii., margine externo tegente. 



One fresh specimen (somewhat crushed in extraction) and a 

 few perfect valves were found of this species, which is charac- 

 terized by the very strong row of tubercles, (like pebbles) which 

 lie on the diagonal line ; by the rows of somewhat strong tuber- 

 cles on the central area, running perpendicularly from the 



