To place the matter in as clear a light as possible, I Avill briefly re- 

 capitulate the characters by which we may distinguish the Harlani 

 from the spinosus. 1. By its greater size. 2. The greater width of 

 the glabella, and the form of its frontal lobe. 3. The great width of 

 the cephalic limb, the shortness of its lateral portion, and the distance 

 to which it is removed from the thorax. 4. The shortness of the 

 movable cheek, and the shape of its posterior lobe. 5. The different 

 position of the palpebral lobe, and its less convexity. 6. The greater 

 length of the curve of the pleurge, and the probable extension of the 

 last one beyond the pygidium. 7. The width of the hypostome, and 

 the long oval form of its anterior portion. 



After citing these differences it gives me pleasure to quote the fol- 

 lowing paragraph from the communication of M. Barrande, both 

 because it strengthens my own conclusion, and shows the knowledge 

 and forethought of the learned author. After speaking of the points 

 in which P. Harlani seems to agree with P. spmosus, he says : 

 " Pour completer ce parallele, il nous manque encore 1' hypostome du 

 Paradoxides americain. C'est seulement dans cette piece, dans les 

 contours exterieurs de la tete et dans les pointes genales, qu'il pourrait 

 se trouver quekpies differences inattendues et contraires a 1' indentite 

 apparente dans toute les autres parties du corps." Now it is precisely 

 in these points, which with his characteristic foresight M. Barrande 

 pointed out, that we find the most marked differences of P. Harlani 

 though I think that I have also shown differences in some other parts. 



My conclusion does not in the least weaken the arguments which 

 have been brought forward to prove the existence of the Primordial 

 fauna in America, but rather indicates the diversity of life in those 

 early ages, and perhaps the distribution of animals into geographical 

 fauuEe, as in later years. 



On the Occurrence of other Fossil Forms at Braintree, 

 Mass. By Albert Ordway. 



At one of the past meetings of the Society, there was exhibited 

 the cast of a fragment of rock from Newfoundland, on which were a 

 number of specimens of Trilobites, which were referred to the genus 

 Conoceplialites, and of which Mr. Marcou spoke in his interesting 

 paper " On the Primordial Fauna," under that name. (See Proc. 

 Bost. Soc. Nat. Hist. vol. vii. p. 369.) From a comparison of this 

 cast, with specimens from Bohemia, I am inclined to refer the speci- 

 mens to the genus ElUpsocephalus^ as they have not the narrowing of 

 the glabella in its anterior part, which is characteristic of Conocepla- 

 lites, nor do there appear to be any furrows on the glabella. The 

 specimens are, however, somewhat imperfect, and having only seen a 

 cast, I would not pretend to speak with much certainly on this point. 

 Which ever genus they may hereafter be found to belong to, it does 



