240 Mr. E. Billings on the Genus Athyris. 
been made by him and Mr. Custos Dormitzer, of Prague. He 
showed that some of the forms heretofore referred to Terebratula 
had no opening in the beak for the passage of the muscle of adhesion, 
and also that the distribution of their inner organs points to an 
affinity with the non-attached genus Pentamerus. These inner 
organs are borne by six partitions in place of a single calcareous 
loop; the spiral arms are not unrollable. 
“Through the separation of these forms (for which the name 
Merista is proposed) from the genus Terebratula, an apparent con- 
tradiction in the laws of paleontological distribution is solved, since 
those smooth forms will now be separated which have heretofore 
offered an apparent contradiction to the present views of these 
laws.” 
Lest I should not have expressed his views rightly in this — 
free translation, I give the original in the note below*. 
On page 160 of the same work there are some further re- 
marks on the classification of the Brachiopoda, by Prof. Suess, 
in which he refers to the genus Merista. No generic description, 
however, is there given. It appears also that it was again 
noticed in Leonhard’s ‘ Neues Jahrbuch,’ 1854, p. 127. I have © 
not at present access to that work, and do not know whether 
the genus is described there or not: at all events, at the time 
Mr. Davidson prepared the English edition of his ‘ General 
Introduction,’ Merista was not understood. 
Prof. King, in his ‘Monograph of the Permian Fossils of 
England’ (1850), proposed to restore the genus Cletothyris of 
Phillips, apparently making it partly equal to Athyris, M‘Coy. 
But the specimen on which this arrangement was founded was 
afterwards shown to Mr. Davidson, and by him identified with 
T. scalprum, Barrande (now Merista scalprum), while Cleiothyris 
was intended by its author as a substitute for dtrypa. (See 
Davidson’s ‘Introduction,’ p. 85.) 
* “Herr Eduard Suess theilte die Erfolge der Untersuchung einiger 
Brachiopoden aus dem bohmischen Uebergangsgebirge mit, die er gemein- 
schaftlich mit Herrn Custos Dormitzer in Prag angestellt hatte. Er zeigte, 
dass mehrere bisher zu den Terebrateln gezahlte Formen an ihrer Spitze 
keine Oeffnung fiir den Anheftungsmuskel besitzen, und dass auch die 
Vertheilung ihrer inneren Organe auf eine Verwandtschaft mit der eben- 
falls nicht angehefteten Gattung Pentamerus hinweist. Diese inneren 
Organe werden von 6 Wanden, statt von einer einfachen Kalkschleife 
getragen; die Spiralarme selbst sind nicht aufrollbar. 
‘‘Durch das Lostrennen dieser Formen, fiir welche der Name Merista 
vorgeschlagen wird, von der Gattung Terebratula, wird zugleich ein 
scheinbarer Widerspruch in den Gesetzen palaontologischer Verbreitung 
gehoben, da eben jene glatten Arten ausgeschieden werden, welche den 
bisherigen Ansichten iiber diese Gesetze am schroffsten entgegengestanden 
waren.”—Jahrbuch der k. k. geologischen Reichsanstalt, Vienna, ii. pt. 4. 
pp. 150, 160: 1861. 
