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Ceratospyris laventaensis
Campbell and Clark, 1944
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Description - Add description
Ceratospyris (Lophospyris) laventaensis
Shell strongly bilobate, relatively large, divided by a deep and wide median vertical stricture into two equal lobes or hemispheres, whole shell 0.8 transverse diameter in length; great-circle a thin, prismatic hoop from which arise longest of coryphal horns; pores circular to elliptical, some very much larger than others, often in pairs or groups of three to five, possibly about 30 on one hemisphere, shallow, with extremely thin mats of semitransparent, shell-substance around each single large one or group-sets of several within a common mat, these polyporous mate in turn enclosed by a thin, polygonal, prismatic network of black bars often but not always forming hexagons of various sizes, depending upon size of enclosed pores, and network as a whole resembling a wire-work basket, from bars of which arise frequent (mostly lateral and coryphal), short, recurved thorns so that surface is prickly; coryphal surface with five (six) long, needlelike, distally sharp spines, two (caudal) of which arise in connection with great-circle and are longer then other three (four) spines which are mostly frontal (and lateral); feet broken in nearly all our specimens but apparently seven, descending, divergent, straight, four-angled in section, with thick decurrent outer, free angles, as long as longest coryphal horns, and distally sharp; interspaces between legs low arches. Diameter of greatest width, 130 µ.
Ceralospyris laventaensis n.sp. differs from aguanegraensis n.sp. in remarkable grouping of pores within polygonal frames, lack of sail-like shell-substance around thorns and spines, longer coryphal horns, and in greater open-work in polygonal mesh. | | Campbell and Clark 1944 |
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