231 



Jlavescente, epidermide tenuissima ; striis incrementi exillimis, 

 ligamento subexterno ; dentibus cardinalibus parvis ; lateralibus 

 antico in utraque valva acuto, postico subobsoleto ; cicatricibus 

 muscularibus, antica a cardine remota, elonyata, intus crenulata ; 

 postica irregulariter pyriformi ; linea pallii margini appropin- 

 quante. 



Long. -76, lat. -89, alt. '57 poll. 



Hab. Mazatlan. Mus. Cuming. 



In shape like Lucinopsis undata ; remarkable for the anterior 

 lateral teeth. 



10. Chiton montereyensis. 



C. t. ovata, subelevata (ad unguium 120°), sublcevi ; olivacea, valva 

 utraque ad jugum rubro-fusco maculata, Ihieis tenebrosioribus 

 valvis intermediis subradiantibus, valvis ultimis radiantibus; valvis 

 intermediis lineis diagonalibus subdistinctis, ad marginem subqua- 

 dratis, suturis conspicuis ; areis lateralibus lineis paucis radian- 

 tibus obsoletis ; tota superficie punctulis creberrimis conferta, 

 subobsoletis, maxime ad areas laterales ; mucrone vix prominente ; 

 Umbo coriaceo, ad marginem et in suturis piloso, setis planatis, 

 curtis, incurvatis ; intus valvarum marginibus haud valde arcuatis, 

 sinu parvo, ad jugum subimpresso. 

 Long. 2-4, lat. T42, alt. -45 poll. 



Hab. Monterey, rupibus ad undarum tumultum expositis : legit 

 — Hartweg. Mus. Cuming. 



Margin with numerous but not crowded, short, incurved, horny, 

 flattened hairs ; shell very finely sculptured, dark olive, with very 

 dark rays slightly diverging from the summit of each valve, and very 

 conspicuous on the terminal one. The jugum is stained in each 

 valve with sienna. 



11. Chiton hartwegii. 



C. t. ovata, subelevata (ad angulum 125°), subltsvi ; olivacea, macula 

 nigra in utroque jugi latere picta ; valvis si?ie lineis diagonalibus, 

 partim detritis, lineis incrementi conspicuis, tota superficie minu- 

 tissime irregulariter subgranulosis ; marginibus rotundatis, suturis 

 magnis ; Umbo tenui, granulis minimis, confertissimis, irregulariter 

 munito ; intus valvarum marginibus arcuatis, lobis prominentibus, 

 sinu lato, haud alto ; ad jugum vix impressus. 

 Long. 1-26, lat. '76, alt. -18 poll. 



Hab. Monterey, cum prsecedente : legit idem diligentissimus. 

 Mus. Cuming. 



A much smaller shell than the last, almost destitute of sculpture ; 

 with a blackish spot on each side of the jugum, but no radiating 

 lines. 



12. Chiton nuttalli. 



C. t. " Chitoni Hartwegii" simili, sed latiore, depressa (ad angu- 

 lum 1 30°), superficie granulis majoribus, maxime marginem versus: 



