82 



G. LINDSTRÖM, HELIOLITID^. 



Some of the Lower Silui-ian Heliolitidic have the distinguishing feature of a scarce 

 coenenchjTna and of closely placed calicles. This may pei-haps, taken together with the 

 developrnent of the polypary of Heliolites, indicate a löst stage of early or ancestral forms 

 of Heliolitidaä in which there was no coenenchyma at all developed and that this catne 

 in by and by. 



The stratigraphical occurrence of the species is as follows, more detailed notes 

 are given in the special descriptions. 



Exclusively Lower Siluriun. 

 Heliolites hirsutus n. 

 Proheliolites dubius Fr. Schmidt. 

 Propora bacillifera n. 

 Prop. cancellata n. 

 Coccoseris Ungerni EiCHW. 



3 raicroporus EiCHW. 



» megastoma M'CoY. 



» var. minor. 



» niicraster n. 



Protarsea vetusta J. Hall. 

 Acantholithus lateseptatus n. 



Common to Loiver and Ujy. Siluri 

 Heliolites interstinctus L. 

 Hel. parvistella F. RoBM. 



» var. intricatus. 

 Propora tubuiata var. LONSD. 



» conferta E. H. 

 Acantholithus asteriscus F. Roemer. 



Only Upper Silurian. 

 Heliolites Barrandei var. spongodes. 

 » fasciatus n. 



» repletus n. 



» Liljevalli n. 



Cosraiolithus ornatus n. 



» halysitoides n. 



Plasiiiopora petalifonuis Lonsd. 

 » foroensis n. 



9 calyculata u. 



» var. tuberosa n. 



» seita E. H. 



» follis E. H. 



» Stella 11. 



» scala n. 



» rosa II. 



» suprenia u. 



» rudis n. 



» heliolitoides n. 



» reticulata n. 



Propora tubuiata LoNSD. 



» conferta var. minima n. 

 » euryacantha n. 

 » speciosa Billings. 

 » compacta n. 

 » ambigua n. 

 Camptolithus papillatus RoMlNG. 

 Diploepora Grayi E. H. 

 Pycnolithus bifidus n. 



Co7nmon to Upper Silurian and Devoniaii. 

 Hel. interstinctus L. 

 Hel. Barrandei Penecke. 



Only Devonian. 

 Heliolites porosus GoLDt. 



In this memoir fourty-six species and varieties have been described, but of course 

 this does not comprise all hitherto known of which several must be classed as synonyms 

 to older. Nevertheless the following list of the distribution of the Heliolitid^e must of 

 necessity be very incomplete in as far as it treats of other countries than the northern 

 and no doubt a greater number is to be found in extra European countries, of which I 

 have had no notion. 



Sweden. 

 Scania. 

 Heliolites interstinctus-decipiens M'CoY. 



Wester götland. 

 Propora conferta E. H. 



Isle of Öland. 

 Heliolites hirsutus n. 

 Propora conferta E. H. 

 Propora bacillifera n. 

 Propora sp. 

 Coccoseris megastoma vai'. minor. 



