24 



IIAEHL AND ARNOLD— THE MIOCENE DIABASE. [Feb. 5, 



"^Arca canalis Conrad 

 Area trill neat a Conrad 



"^ Astrodapsis n. sp. Merriam 

 A sty r is richihofeJii Gabb 

 Balanus esirellanus Conrad 



'^Bucciniwi n. sp. A. 



* Calliostoma n. sp. A. 

 Callista angustifrons Conrad 



* Cancellaria n. sp. A. 

 Cardium 7neekianum Gabb 



* Cardium meekia7ium n. var. A. 

 Chrysodomus liratus Martyn 

 Chrysodomiis tabulatus Baird 



^ Ch?ysodo7?tiis n. sp. aff. tabu- 

 latus 



Crepidula grandis Midd. 



Crepidula rugosa Nuttall 

 ^ Crypto 7fiy a n. sp. aff. calif omica 

 "^Dolichotoma n. sp. aff. carpen- 

 teriana 



Drillia incisa Carpenter 



Galerus ma77imillaris Broderip 



Glottidia albida Hinds 

 '^Lczvicardiiwi n. sp. aff. substri- 

 atiwi 



Leda cf. fossa Baird 



Leda taphria Dall 



Luci7ia acutilineata Conrad 



LuTiatia lewisii Gould 



Maco77ia iiiquitiata Deshayes 



Ma coin a nasiita Conrad 



Mactra calif omica Conrad 

 Mactra falcata Gould 

 Modiolus rectus Conrad 

 Mytilus 77iaihewsonii Gabb 

 Nassa califor7iiana Conrad 

 ^^Neptunea huTnerosa Gabb 

 Nucula castre7isis Hinds 

 Olivella i7ito7-ta Carpenter 

 Olivella pedroana Conrad 

 Panomya a77i('la Dall 

 Panopea ge7ierosa Gould 

 Pecte7i expa7isus Dall 

 Pccte7i hastatus Sby. (smooth 

 var.) 

 ^Pecten n. sp. aff. expansus 

 '^Pecte7i n. sp. aff. dilleri Dall 

 "^ Pec ten n. sp. aff. par7neleei 

 '^ Priene oregone7isis Redfield (n. 

 var. ?) 

 Purpura crispata Chemnitz 

 Rosiellaria indurata Conrad 

 Saxido77ius gibbosus Gabb 

 Scutella i7iterli7ieata Stimpson 

 Siliqua patula Dixon 

 Solariella pera77iabilis Carpen- 



ter 

 Tapes staleyi Gabb 

 Tapes te7ie7^ri77ia Carpenter 

 Telli7ia aff. congesta Conrad 

 Tresus nuttalli Conrad 

 * Valuta n. sp. 



Relation of the Diabase to the Associated Sedimentaries. 



The masses of diabase follow the bedding, particularly in the 

 shale of the lower Miocene series, and it is in between shale beds 

 that most of the diabase exposures occur. Fig. 2 shows some shale 

 beds resting against a large diabase dike which crosses the Sears- 

 ville-La Honda road near the summit of the Santa Cruz range. 

 The diabase dike in this case was intruded between and followed 



