P L A T 1-: X XX. 



I'l.IliCKM'. I'KCTKXS. 

 [I'nlrss (itluTwisi- stilted all liiiiircs iin- jiiipnixii]iati'l\ luitiiral sizt'.] 



Page. 



99 



Fii;. 1. Pi'rliii { /'I'ch'ii.) iiierriiniii ii. ,-|i. ('. S. >1. 11. '\\]n' 



Kxtiriiir (if imperfei't liylil \:ilvf; siltitiidc 1-0 iiiiii. I'linfi'iie, ririi (.'i-ei'k, Vfiitma 

 Ciitiiily, Cal. (M. B. 1 

 Im(.. Ik. Same s|i(.'i-iiiien a^ tiij. I. rtcililc of Imtli valvc;^ as viewiil t'l-om tlie rear. ( M. I\ ). . . . 99 

 I'k;. 2. Piyten {I'crtfii) nierrinmi n. sp. ( '. S. .M. l'>. ('(ityiif 99 



E.xterioi- nf impertVct U-ft \alvi', altitudr 110 mm. Samt' locality as lig. 1. (JI. 13.) 



L'(I4 



