21S C. E. Beecher — Koninckina and related Genera. 



spira, and this position is further fortified by recent investi- 

 gation. Thecospira has been mentioned as furnishing an 

 apparently abnormal character in the presence of a pedicle- 

 sheath, to which should be added its condition of fixation by 

 the ventral valve, and the punctate shell structure. Otherwise 

 the features described and illustrated by Zugmayer appear to 

 agree in all essential particulars with Koninckina. 



Therefore, it is believed, that the genera Davidsonia and 

 Ccelospira should be omitted from the family, and that The- 

 cospira and Anoplotlieca should be allowed to remain tenta- 

 tively until further information is obtainable. 



The relations of the genus Kayseria (Davidson, 1882,) to 

 this group have previously been discussed simply with refer- 

 ence to the duplicate nature of the spirals,* but from what 

 has been shown regarding the attachments and the loop of the 

 primary lamellae, as well as the articulation with the dorsal 

 septum, and the additional hinge characters in Koninckina, 

 further important relationships may be adduced which it is 

 believed will remove Kayseria from the Athy rinse, and place 

 it with the forms treated of in the present paper. Tn a recent 

 study of Kayseria, the writer has found no particular in which 

 to change the details of the spirals so completely determined 

 by the Rev. N". Glass for Mr. Davidson. f The only additional 

 features to be noted are relative to the shell, and consist of a 

 collosity under the dorsal beak forming the median septum, 

 the well-developed cardinal processes, and the impunctate 

 structure of the test. A comparison in the light of those 

 facts reveals a striking similarity in most of the important 

 features. 



The position of this group in the last systematic arrange- 

 ment of families and genera proposed by Davidson now seems 

 to belong, not at the end of the Spiriferacse as placed, but 

 immediately following the At hy rinse and preceding the Atry- 

 pinse. It is not necessary in this place to discuss the merits of 

 these groups to rank as families, and the importance accredited 

 to them by Davidson is here retained. 



Sub-family Kbninckinince, emend. — Diagnosis. Ventral valve 

 perforate and with a hinge area, sometimes obscured by 

 the involution of the beak, with or without deltidial plates. 

 Dorsal valve with cardinal processes and median septum, upon 

 some point of which the loop of the primary lamellse articu- 

 lates. Brachial supports composed of two primary lamellse 

 connected by a loop from which originate two secondary 

 lamellse, extending to the apex of the spiral and following its 



* British Fossil Brachiopoda, General Summary, p. 369, 1884. 



f Ibid., Supplement to the Devonian Brachiopoda, pp. 22-23, 1882. 



