NO. 2 BRACHIOPOD SUPERFAMILY STENOSCISMATACEA GRANT l6l 



translation. The following excerpt is relevant here : "About the inner 

 structure of the shell, I can say nothing. With a strong lens two diverg- 

 ing dark lines can be seen on the shell surface near the beak of the 

 ventral valve. These correspond to the characteristic septa [of this 

 genus]" (insert by Grabau). The genus meant is Camarophoria. Ob- 

 viously, if there are two diverging septa (dental plates) along the 

 floor of the ventral valve, no spondylium is present, and the species 

 does not belong to "Camarophoria" 



Text-figure 7 of Grabau (1931b, p. 86) shows sketches of apical 

 cross-sections of two specimens that he identified with Loczy's species. 

 If they are accurate (and there is no reason to doubt that they are) a 

 spondylium clearly is present in the pedicle valve, elevated on a median 

 septum, and no diverging septa could appear along the valve floor. Two 

 explanations are plausible, one that Loczy saw the septa near the apex, 

 where the spondylium is sessile, the other that Grabau's and Loczy's 

 specimens are not conspecific (nor congeneric) . 



Grabau's sketches (1931b, text-fig. 7) show a spondylium in the 

 pedicle valve, the shape of which is normal for stenoscismataceans in 

 fig. a, slightly different in fig. b. Either would be considered well within 

 the limits for the superfamily if accompanied by a camarophorium in 

 the brachial valve. However, neither sketch shows a camarophorium, 

 only an unmodified short median septum. If these specimens were 

 stenoscismatacean, the septum would not extend anteriorly farther 

 than the camarophorium, so the sketches cannot be explained simply as 

 sections anterior to the camarophorium ; furthermore, they purport to 

 show sections fairly near the beaks, and are labeled by Grabau as 

 "apical sections." 



The internal structure of Grabau's Camarophoria sutschuanensis 

 Loczy is not that of a stenoscismatacean genus ; probably the species 

 belongs to an undescribed genus. Possibly it is an off-shoot from the 

 stenoscismatacean line, in which the camarophorium has degenerated. 

 It may represent a more normal rhynchonelloid genus in which no 

 camarophorium ever existed, but the dental plates united to form 

 a spondylium. The usual trend in brachiopods is for the structures of 

 the brachial valve to be more conservative than those of the pedicle 

 valve (Ulrich and Cooper, 1936) . Study of brachiopods shows that the 

 spondylium is a structure that recurs in many groups. These considera- 

 tions favor the alternative that C. sutschuanensis is unrelated to the 

 Stenoscismatacea, but externally Grabau's specimens closely resem- 

 ble other stenoscismatacean species from the Chinese Devonian. This 

 equivocal evidence leaves the position of C. sutschuanensis indetermi- 

 nate, until the type specimens can be studied directly in relation to 

 other species from the Chinese Devonian as well as to species of other 

 genera in the superfamily. 



