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PHILONYX Richter and Richter, 1952. Two views of Philonyx philonyx Richter and Richter, Hamar Laghdad Formation, L. Devonian, Alnif, Morocco (xl.9). These plates offer another glimpse at the extravagant and delicate trilobite structures that have been uncovered recently by the expert use of airabrasive techniques. For Pbilonix also, a formal description of the complete morphology is still lacking. As seen in this example, the anterior border of the cranidium projects forward in an upturned, four-pronged, forklike process about half of the length of the glabella. The anterior part of the glabella is adorned by three pairs of prominent tuberculi, the occipital ring carries a medial long, elevated, flattened spine which arches backward and reaches the sixth to the seventh thoracic segment. The prominent schizochroal eyes support a long slender spine arching backward from the palpebral lobe margin. [he genal spines arch out and project backward, reaching the eighth segment; a pair of metagenal spines is present. The thorax has twelve segments. Three sets of long slender spines jut out vertically, arching backward, one set from the center of each axial ring, the other rwo from the pleural margins. The hook-shaped pleural spines progressively increase in length. The pygidium has nine axial rings armed with spines and a terminus merging into a short axial spine, five pairs of pleural ribs separated by deep, broad furrows. The ribs merge into five pairs of broadly arched, long spines, distinctly more robust than the thoracic pleural spines. Somewhat unfortunately, it has not been possible to whiten these highly valued specimens for a more thorough study. (RLS id.; photographed by the author, through courtesy of Robert Carroll, who prepared the specimen.)

GREEN OPS (NEOMETACANTHUS) Richter and Richter, 1948. Greenops (Neometacanthus)

steUifer (Burmeister), Hamar Laghdad Formation, L. - M. Devonian, southeast of Erfoud, Morocco (x5.8). Specimen prepared by Flavio Bacchia, whitened with magnesium oxide. (RLS coll., id.)

METACANTHINA Pillet, 1954. Metacantbina barrandei (Oehlert), Devonian, Alnif, Morocco (x4.1). Specimen whitened with magnesium oxide. (RLS coll., id.)

GREENOPS Delo, 1935. Greenops (Greenops) boothi (Green), Windom Formation, Devonian, Windom, New York. (Loaned by Orton Museum, Ohio State University, through courtesy of Stig N. Bergstrom.) In (a) (x3.6) the specimen is coated with magnesium oxide. Note how surface details are emphasized. Part (b) (x4.4) shows the uncoated specimen. There is dramatic color contrast, but most of the surface structure is not visible. The eyes in this specimen have been lost.

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Greenops (Greenops) boothi (Green), Moscow Formation, M. Devonian, Alden, New York (x5.6). A delightful association of two complete individuals. (RI. S coll., id.)

TREVEROPYGE Struve, 1958. Treveropyge sp. Devonian, Alnif, Morocco (x3.6). Note the prominent schizochroal eyes of this dalmanitid ttilobite. (Loaned through courtesy of David C. Rilling.)

Family Calmoniidae Delo, 1935

Subfamily Calmonnnae Delo, 1935

METACRYPHAEUS Reed, 1907. Metacryphaeus venustus W o l fa r t, L. Devonian, Patacamaya, Bolivia (x5). (a) Side view, showing the schizochroal eye, lenses not preserved; (b) top view. The prominent surface tuberculation is remarkably well portrayed. Specimen whitened with magnesium oxide. (RLS coll., id.)

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