------------ nephrocarpa, [113].

Spicula of sponges, [234], [238].

Spiders, fossil, [550].

Spinax major, [580], [584].

Spines of Cidarites, [319].

Spiniferites palmatus, [241].

------------ ramosus, [239], [240].

------------ Reginaldi, [239], [241].

Spirifer trigonalis, [390].