LOWER CAMBRIAN. 49 



DESCRIPTION OF GENERA AND SPECIES. 



Genus MEDUSINA Walcott. 



Medusites Germar, 1S26. Geogn. Deutschland, Vol. I V, 1826, p. 108, PI. la, figs. 8-10. 

 Mtdusites Haeckel, 1805. Zeitsehr. fur wiss. Zoologie, Vol. XV", p. 513. 



The genus Medusites was proposed by Professor Germar for some 

 problematic fossils that were referred to Lumbricaria by Dr. Goldfuss. 1 

 This appears to be a correct reference, judging from Germar's figures. 

 Medusites is, therefore, a synonym of Lumbricaria; and Medusina is pro- 

 posed as a generic term to include all species of fossil medusa; whose 

 generic characters can not be determined. 



Medusina costata Torell (sp.). 



PI. XXIX, figs. 1, 2, 3a-b. 



Spatangopsis costata Torell, 1870. Lunds Universitets Ars-Skrift, 1809, No. VIII, 



p. 11. 

 Agelacrinus f lindstromi Liunarsson, 1871. Kougl. svensk. Vet.-Akad. HandL, vol. 



9, No. 7, p. 11, PI. I, figs. 6-9; PI. II, figs. 10-14. 

 Medusites lindstromi Nathorst, 1881. Kongl. svensk. Vet.-Akad. Hand!., vol. 19, No. 



1, p. 25, PL IV, figs. 1-10; PL V, figs. 1-4. 

 Medusites lindstromi Schmidt, 1888. Mein. Acad. imp. sci. St. Pctersbourg, 7th 



series, Vol. XXXVI, No. 2, p. 27, PL II, figs. 34, 35. 

 Medusites eostatus Matthew, 1890. Trans. Royal Soc. Canada, Vol. VIII, Sec. IV, p. 



142. 

 Medusites lindstromi Walcott, 1891. Tenth Ann. Rept. U. S. Geol. Survey, Part I, PL 



LVI, figs. 1, la-c. 



Original description: 



Infra globosa, supra obtuse conica, costis 5 acutis, ex apice excentrico radiau- 

 tibus, prope marginem desinentibus. In parte inferiore cujusque arete iutercostalis 

 eminentia fere seiniglobosa costas uon attiugens. Alt. circiter 30""", lat. 32 mm , speci- 

 minis depressi prope 50™'". 



Locus: In saxo arenaceo formationis cambricse ad Lugnas et Timmerdala in 

 monte Billingen, Vestrogothise. 



Dr. Torell referred the species with doubt to the Echinodermata. 1 >r. 

 Liunarsson referred it tentatively to the g - enus Agelacrinus, and described it 

 in part as follows: 



These echinoderms are among the most remarkable of the fossils of the Eophyton 

 sandstone. They vary greatly in form and size. No part of the shell is ever found 



1 Petrefaota Germanise, 1826-33, Vol. I, p. 222. 

 MON XXX 4 



