I46 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. I48 



the crest of the fold. It is about the same size as S. hueconianum 

 (Girty) but is much less globose and with fewer, broader costae, and 

 more consistently present stolidium. It is much smaller than 5\ venus- 

 tum (Girty) ; its outline normally is more transverse, stolidium some- 

 what shorter, fold proportionately higher, and costae are much broader, 

 fewer, and begin farther anteriorly. S. schlotheimi is less strongly con- 

 vex and has a much smaller number of costae than S. inequale (Girty). 

 It is much less convex and more transverse than 5*. thevenini (Koz- 

 lowski) from the Permian of Bolivia, and has fewer costae, especially 

 on the fold. It is similar to the Texas Permian species that King 

 (1931) identified as S. thevenini, differing primarily in its higher fold, 

 somewhat more transverse outline, weaker costae, and shorter pedicle 

 beak. 



This species is much smaller and more weakly costate than S. multi- 

 costum Stehli and, although only about half as large as typical for 5". 

 kalum Stehli, it has many fewer and much weaker costae. 5\ schlo- 

 theimi is much smaller than S. purdoni (Davidson) identified by Broili 

 (1916) from the Permian of Timor. Furthermore, its is proportion- 

 ately wider and less convex than the Indonesian species. It is much 

 smaller, also, than 5. giganteum (Diener) from the same island, and 

 has fewer costae that begin farther anterior. 



5". schlotheimi is smaller and has fewer and weaker costae than any 

 of the species described by Waagen (1883) from the Permian of the 

 Salt Range, excepting "S." superstes (Verneuil) (now considered a 

 species of Cyrolexis) and "S. globulinum" (Phillips) ; it is much wider 

 and less globose than either of those two species. Among the species 

 identified from the Permian of the Urals and Timan by Tschernyschev 

 (1902), only 5. crumenum (Martin) and some specimens of S. muta- 

 bile (Tschernyschev) resemble the type species. But neither of these is 

 as wide, both are more globose, and S\ mutabile is much more strongly 

 costate in the adult stages. 



Among British species, 5". multiplicatum (King) is larger and more 

 costate than S. schlotheimi; Terebratula globulina Phillips (now in 

 Coledium) is smaller, rounder in outline, and has proportionately more 

 prominent mesial costae. 5. crumenum (Martin) is larger and its costae 

 are more numerous and begin farther posterior, in addition, the profile 

 is more strongly convex. 



Occurrence and age. — The species is abundant in the fossiliferous 

 part of the Zechstein near Possneck, Germany (Late Permian accord- 

 ing to Gignoux, 1955, p. 214) . It has been identified widely throughout 

 Europe, but these citations probably do not reflect accurately its true 

 distribution. Until European specimens can be compared in detail, only 

 those from the type area can be considered reliably identified. 



