264 ' SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 53 



MESONACIS TORELLI (Moberg) 



Plate 26, Figs. 5-18 



Olenellus iorelli Moberg, 1892, Om Olenellusledet i sydliga Skandinavien, 

 p. 3. (Specimens exhibited at 14th meeting of Scandinavian natural- 

 ists at Copenhagen discussed.) 



Schmidtia ? torelli Moberg, 1899, Geol. Foren. i Stockholm Forhandl., Bd. 

 21, Hafte 4, pp. 330-338, pi. 15, figs. 1-17. (Described and discussed in 

 Swedish. Figures ib, 4, 6, 7, 8, 10, 12, 15, and 16 of Moberg are copied 

 in this paper, pi. 26, figs. 5a, 7, 9, 17, 16, 18, 14, 11, and 15 respectively. 

 Plaster casts of the specimens represented by figures la, 6, and 14 of 

 Moberg are figured in this paper, pi. 26, figs. 5, 10, and loa, and 8 

 respectively.) 



Dr. Joh. Chr. Moberg gives a very full description of this inter- 

 esting species as represented by numerous fragments of the cephalon 

 and thorax and entire specimens of the pygidium. Dr. Moberg very 

 kindly sent me casts of the specimens he used for illustration, also 

 a few natural specimens. From the casts and specimens a few fig- 

 ures have been made that will serve to indicate the principal char- 

 acters of the species. 



The generic reference is based on the general similarity of the 

 cephalon and pygidium to that of Mesonads vermontana [pi. 26, 

 fig. I ] , the presence of a thoracic segment bearing a large spine, and 

 the fact so well stated by Dr. Moberg that the central lobe of the 

 thorax was about as wide as half the width of the thorax, this indi- 

 cates a slender thorax similar to that of M. vermontana. 



OholeUa Imdstromi Walcott, O. niobergi Walcott, and a Hyolithes 

 like H. degeeri Holm occur with fragments of M. torrelli. 



Formation and Locality. — Lower Cambrian: (312V) bluish- 

 gray sandstone, along the coast near Bjorkelunda, south from Shn- 

 rishamn, Province of Kristianstad, Sweden [Moberg, 1899, p. 337]. 



The species is doubtfully identified by Moberg [1899, p. 337] in 

 sandstone occurring between Sularp and Norrtorp, near Fogelsang, 

 Province of Malmohus, Sweden. 



MESONACIS VERMONTANA (Hall) 



Plate 26, Figs. 1-3 



Olenns vermontana Hall, 1859, Twelfth Ann. Rept. New York State Cab. 



Nat. Hist., pp. 60-61, fig. 2, p. 60. (Described and discussed as a new 



species.) 

 Olenus vermontana Hall, 1859, Nat. Hist. New York, Paleontology, Vol. 3, 



pt. I, p. 527, text figure. (Copy of the preceding reference.) 



