KONGL. SV. VET. AKADEMIENS HANDL. BAND. 19. N:0 6. 71 



as Mac Coy already had done before him. But there is no reason to couple them 

 with the CapulidiB as Ihering does, when he thinks that Carinaropsis is the connec- 

 ting link. This genus is no doubt composed of incongruous elements, some being real 

 Bellerophons, others Capulida; or even Patellidaj. The remark of Stoliczka that the 

 Lepetida3 are near to Cyrtolites (»Some of the species of Anisomion exhibit a great 

 relation to species of the palajozoic Cyrtolites, like C? expansus»), löses all its founda- 

 tion, as it is evident that Cyrtolites expansus of Hall is no Cyrtolites, but a Platy- 

 ceras. 



Meek (1. c.) lays, as it is quite right to do, much stress on the affinity of Tre- 

 manotus with Bellerophon and Bucania on the one side and with Haliotis and Pleuro- 

 tomaria on the other. He concludes: »In other words it indicates for the family a 

 position near the Fissurellidn3 and Haliotidas, and between these groups and the Pleu- 

 rotomaridfe». 



VVaagen (1. c. p. 130) holds the opinion that a more or less close affinity of the 

 Bellerophontida? to the Pleurotomaridas is highly probable. What makes the Bellero- 

 phons approach the Pleurotomarite is a tendency observed amongst some to grow some- 

 what obliquely, thus nearing to the conical spiral. In accordance with De Koninck^) as 

 this author formerly has stated, I do not think it advisable as Waagen has done, to place 

 within this group such forms, which, although resembling the Bellerophons in the 

 general form of the shell, do not show the least trace of apertural sinus nor of any 

 slit band. De Koninck holds that such are young Goniatites and it is remarkable that 

 in the Silurian formation, where no Goniatites are found, also such Bellerophon-like 

 shells without any slit band are wanting. Such forms are comprehended in the new 

 genera, which Waagen (1. c.) has proposed under the names Warthia, Mogulia and 

 Stachella. The same is also the case with Meek's Bucanella and Mac Coy's Euphemus, 

 though De Koninck and Waagen have again adopted the last genus. The slit band 

 must indeed be considered as one of the most important, if not the most prominent 

 character of the shell itself. Still it is very difficult absolutely to decide this as well 

 as other cases of affinity amongst the palteozoic shells, as there may be other genera 

 as for inst. Scissurella, with a distinct slit band on the shell, without any affinity be- 

 tween the animal itself and that of Pleurotomaria. 



For my own part, I feel inclined to follow the precedence of Meek and accept 

 the Bellerophontidaa as most nearly related to Haliotis, a view in which De Koninck 

 also in his last work participates. This view is strengthened by the similarities which 

 are offered by Tremanotus with its perforated slit band and the sculpture of the sur- 

 face which in so eminent a degree reminds of that of Haliotis. This position, however, 

 cannot but remain hypothetical, as no more valid grounds taken from interiör resem- 

 blances and homologies between the soft parts of the animals can be gained. Nor is 

 there anything in the microscopic structure of the shell that either corroborates or 

 contradicts such views. Not the least trace of anj' nacreons stratura has been found 

 in the Gotlandic Bellerophontidte. 



') Mem. de la Soc. Roy. d. Se. de Liége. 1878, p. ,340. Fossiles paléozoiqiies de la Nouvelle-Galles du Sud. 



