362 GENERAL SUMMARY TO 



constituting a species, though this must be understood " cum grano salis." I am 

 therefore willing to retain the genus Dielasma of King. 



8t/i Genus. — Coinothyris's, Douville ; type T. vulgaris, Schlotheim. 



I am not sufficiently acquainted with the real nature of the loop of this species, as I 

 have never seen it myself, but, judging from von H. C. Koschnisky's description and 

 figures of its interior, the generic characters seem to be substantiated. 1 



Therefore out of the eight genera proposed by Douville, I would retain four only. 

 Terebratulina, d'Orb. ; Terebratula, Klein ; Dielasma, King ; and Canothyris, Douville ; 

 but in this matter I express my own views, but which others may reject. 



In his work above quoted, Dr. Waagen proposes several more genera for the 

 Terebratulida : 



" Rh^etina, Waagen, 1882. Type T gregaria, Schafh ; shell biplicate ; loop short, 

 fixed to the bottom of the valve by septal plates, which sometimes form a septum, 

 sometimes not ; ventral valve without dental plates ; Rhaetic." 



Judging from the figure of the interior of the dorsal valve given by Waagen, the 

 loop seems to be similar in shape and character to that of Terebratula. 



" Zugmeyeri a, Waagen, 1882. Shell biplicate ; loop short ; without septal plates. 

 Strong dental plates in ventral valve. Type Terebratula rhcetica, Zugmayer ; Rhsetic." 



Judging from Herr Zugmayer's figures of the loop of T. rhatica (Uber Rhatische 

 Brachiopoden, pi. i, figs. 29 — 31, 1880), I feel disposed to leave this species in the 

 genus Terebratula. 



" Hemiptychina, Waagen, 1882. Surface of the shell smooth or irregularly folded 

 in the frontal region ; frontal line vaulted ; loop short, like in Terebratula ; with distinct 

 septal plates, which very rarely unite to form a septum. Type Terebratula ffimalayensis, 

 Dav. 



" Dielasmina, Waagen, 1882. Shell strongly but irregularly folded radially; 

 internal arrangement as in Dielasma. Type Diet, plicata, Waagen." 



Although I do not yet see my way to admitting all these genera, I have considered 

 it but just and fair to the distinguished German palaeontologist to reproduce his views 

 upon this subject. 



Dr. Waagen adds that only for one genus does the systematic position remain doubtful, 

 this is Hynniphoria, Suess, 2 in which opinion I completely concur. 



Dr. Waagen condenses his views relative to the Terebratulida in the following tabular 

 form. 



1 " Beitr'age zur Kenntniss von Terebratula vulgaris, Schlotheim " ' Zeitsch. deutsch. geol. Gesell- 

 schaft,' Jahrg., 1879. 



2 " Beitr. Palaont. Oesterr.," Franz von Hauer, Bd. i, Heft. 2, p, 44, t. v, figs. 4—8, 1858. 



