I58 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. I48 



snitskaya and Tetracamera Weller, the former with high and the latter 

 with low lateral buttress plates. Apparently Licharev agreed with 

 Stepanov that lateral buttress plates are present. 



Transverse buttress plates could have been destroyed in Tscherny- 

 schev's specimens when he broke them along the midline. Therefore, 

 I incline to accept tentatively the opinion of Stepanov and, inferen- 

 tially, of Licharev that they are present in the genus. Presence of such 

 buttress plates certainly would make the genus separate from Steno- 

 scisma and Torynechus which lack them. 



Concerning the presence of a camarophorium in Septacamera, 

 authorities again are divided, although majority opinion favors it. 

 Tschernyschev's illustration, which may be considered authoritative, 

 shows clearly the presence of a normal camarophorium, although the 

 anterior part is missing. Stepanov states unequivocally, "There is a 

 camarophorium in the dorsal valve" (p. 149). Licharev (1960) by 

 classifying the genus with the Tetracameridae, seems to argue that no 

 camarophorium is present. However, possibly he considered presence 

 of lateral buttress plates taxonomically more important than a camaro- 

 phorium, and placed Septacamera in that family despite a camarophor- 

 ium. Only examination of topotype specimens can settle this question. 

 Inasmuch as Tschernyschev and Stepanov indicate clearly the presence 

 of a camarophorium, and Licharev is ambiguous on the subject, it 

 seems reasonable to believe that one is present. 



If Septacamera has a camarophorium it belongs with the Stenoscis- 

 matacea, rather than with any other group. Dental plates that unite to 

 form a spondylium definitely are present in the genus ; only the pres- 

 ence of lateral buttress plates is in doubt, and their presence is not 

 sufficiently important to remove the genus from the Stenoscismatacea. 



Stepanov cited the lateral buttress plates as sufficient to separate 

 Septacamera from Stenoscisma. Despite doubt that such plates are 

 present, other valid distinctions from Stenoscisma are notable. Most 

 obvious is lack of a stolidium in Septacamera. The genus occurs in the 

 Permian where nearly all species of Stenoscisma have the stolidium 

 present in full-grown adults. It is absent from large specimens of 

 Septacamera. In addition, the valves of Septacamera meet at the ante- 

 rior in a very gentle (nearly straight) angle, or in a broad arc. Further- 

 more, they tend to become flattened in some species that mimic the 

 uncinuliform anterior of Torynechus (e.g., 5. plicata (Kutorga)), 

 although not to the same degree. 



Until it is possible to examine specimens from the Urals, available 

 evidence indicates that Septacamera is a stenoscismatacean genus re- 

 lated to Torynechus. 



The only species of Septacamera examined at first hand is S. cf. S. 



