no. 1600.. ON THE REVISION OF PTERINEA GOLDFUSS—WILLIAMS. 85 
11. Surface smooth with concentric growth lines of surface entire, 
normally not wrinkled or elevated into radial lines or ribs.“ 
The type of the genus, Pterinea laevis Goldfuss, comes from the 
upper Coblenzian, Ems, Germany. The Ordovician species Pterinea 
demissa of Conrad, and Avicula ampliata Phillips of English Ordo- 
vician may belong to the genus thus emended. 
(? Subgenus) MICROPTERIA Frech. 
Type.—Pterinea ventricosa Goldfuss. 
Pterinea ventricosa 1s shown by Frech” to be separated from the 
group of P. laevis by the continuity of its hinge teeth and by the 
smallness of the anterior ear. The form of convexity of the left 
valve of that species is different from typical Pterinea levis. P. 
ventricosa forms the type of Frech’s division “ gruppe der Pterinea 
ventricosa,” regarding the character of the teeth of which he says, 
“und konnte wegen dieses, an Actinodesma erinnernden Merkmals 
zum Vertreter einer Untergattung (etwa Micropteria) erhoben wer- 
den.”¢ This removes P. ventricosa from the genus Pterinea Goldfuss, 
sensu stricto as here emended. Pterinea bicarinata is a Grammysia. 
Pterinea plana Goldfuss is recognized by German authors as in part 
equivalent to P. lineata. The smooth valves will probably remain in 
the genus Pterinea. 
PTHRINHA LINEATA GOLDFUSS THE TYPE OF A NEW GENUS 
TOLMATA. 
Besides the typical group of Pterineas the original genus of Gold- 
fuss includes several species with distinct radial surface sculpture. 
The Pterineas with fine radial lines were made by Frech the type of 
his “ gruppe der Pterinaea lineata” for which he gave the following 
diagnosis: “ Linke trappe gewOlbt, rechte flach. Radial streifen fein. 
Vorderes ohr undeutlich.” @ This group forms a definite and natural 
section of the original Goldfuss genus Pterinea. In the diagnosis of 
the genus, therefore, belong in addition to the points of difference 
the other positive characters of the original genus, namely, the long 
hinge line, but chiefly posterior to umbones; right valve resupinate; 
4*¥Wrech’s remark that ‘ Pterinea laevis ... zeigt zuweilen Andeutungen von 
Radial rippen” (pl. x, fig. 3 0), (Die Devonischen Aviculiden Deutschland, p. 
50), does not invalidate the restriction above made, but furnishes reason for the 
opinion that generic characters like specific characters can not be regarded as 
absolutely fixed. In the specimen referred to by Frech there is a rudimentary 
puckering of the border of the outer shell lamelle in a late stage of growth. 
It is, however, sufficient to state that this is abnormal to the group of shells to 
which the emended definition of the genus Pterinea Goldfuss applies. 
5 Die Deyonischen Aviculiden Deutschland, p. 97. 
© Idem, p. 80. 
¢Tdem, p. 79. 
