. Brachiopod genera of the suborders Orthoidea and Pentameroidea. Orthoidea; Pentameroidea; Paleontology -- Paleozoic. 132 GENERA OF THE SUBORDERS ORTHOIDEA AND PENTAMEROIDEA actually punctate. Mystrofhora, however, differs so strongly from Skenidium in other details that it could easily have been determined as generically distinct with- out the aid of punctation. The lobate cardinal process, together with the punctation, at once establishes Mystro-phora as a dalmanellid. It differs further from Skenidium in the ventral valve, which has no spondy- lium; instead, the divergent dental plates are
. Brachiopod genera of the suborders Orthoidea and Pentameroidea. Orthoidea; Pentameroidea; Paleontology -- Paleozoic. 132 GENERA OF THE SUBORDERS ORTHOIDEA AND PENTAMEROIDEA actually punctate. Mystrofhora, however, differs so strongly from Skenidium in other details that it could easily have been determined as generically distinct with- out the aid of punctation. The lobate cardinal process, together with the punctation, at once establishes Mystro-phora as a dalmanellid. It differs further from Skenidium in the ventral valve, which has no spondy- lium; instead, the divergent dental plates are attached directly to the floor of the valve. In the apex, grow- ing to the inner sides of the dental plates, is a flat plate, probably for pedicle attachment, similar to that seen occasionally in Schizofhoria and other members of the Schizophoriidas. Discussion.—In describing Mystrofhora, Kayser did not definitely designate a genotype. Underneath. Fig. 21.—Mystrofhora areola (Quenstedt). Section about 2 mm. from the beak, showing relations of apical plate and dental lamellae, x ca. 12. the heading "Subgenus Mystrophora" is placed a refer- ence to Quenstedt's figures. At the end of his discus- sion, he names as typical species "M. Lewisii ; from the Silurian and "M. areola ; in the order here given. Kozlowski^"' makes the suggestion that if future work on Skenidium and Mystrophora should prove the former to be punctate, the name Skenidium could be used for the punctate species and Mystrophora with "M. lewisii" as the type for the impunctate group. In the absence of definite informa- tion one way or the other, he includes both punctate and impunctate forms under Skenidium. It is clear from Kayser's text that he regarded Orthis areola as the type of his subgenus. This view was also held by Williams and Breger,^*"* who say, "The type of Mystrophora was Quenstedt's Orthis ; Schuchert and LeVene'&qu
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