Contributions to Palaeontology. 



109 



" pressions is different. In Obolus, the two central scars 

 " have their smallest extremities directed downwards 

 "and converging towards each other; but in this genus, 

 " the arrangement is exactly the reverse." 1 



Mr. Billings has given, of one of the species of the genus, the 

 accompanying illustration of 11 the interior of one of the valves, 



1 In my Annual Report on the Progress of the Geological Survey 

 of Wisconsin for 1860, I described as Lingula t polita * a fossil possessing 

 characters intermediate to Lingula and Obolus. I remarked that the 

 Bhell had been referred to Obolus by Dr. Owen, but that I was then unable 

 to find satisfactory evidence of the characters of Obolus : neither were the 

 characters those of true Lingula. This Report was in the hands of the 

 authorities, and the first form printed during my stay in Madison between 

 the 25th of February and the 5th of March 1861 ; but the printing of the 

 work was not resumed till the November following, f 



Some time before the middle of December 1861, I received the pamphlet 

 of Mr. Billings, published the 21st of November, containing the descrip- 

 tion of the Genus Obolella. In this pamphlet he cites as one of the 

 genus "a small species from the Potsdam sandstone of the St. Croix 

 44 river in the Western States, where it occurs associated with primordial 

 44 Trilobites described by the late eminent geologist Dale Owen." 



Subsequently my attention was very rudely called to this paper by an 

 article in the Canadian Naturalist by Mr. Billings, charging me with 

 having availed myself of the knowledge given in his pamphlet relative to 

 Obolella, to make the comparisons cited above. The same article, or a 

 Bimilar one, was republished in the American Journal of Science, which 

 has shown a remarkable avidity in publishing anything that might cast 

 reproach upon my labors, or injure me personally. 



The fact that the shell which I had under consideration had been referred 

 by Dr. Owen to Obolus, Obolus apollinus, and Obolus (Apollinus ?) "J, 

 was certainly sufficient to suggest some discussions on its relations to that 

 genus, without a hint from any one. 



Nevertheless, the species cited by Mr. Billings, if the locality be cor- 

 rect, is clearly not the one described by me ; for it does not occur at the 

 Falls of St. Croix, nor on the St. Croix river "in the Western States," so 

 far as I know ; nor am I able to find, in Dr. Owen's Report, any reference 



*In printing of this Eeport, beyond the first form, no proofs were submitted tome, and 

 the quere after Lingula (?) was omitted by the printer. 



t For evidence regarding the date of printing this Report, see Journal of the "Wisconsin 

 Senate, " Fifteenth Annual Session," page 181. 



$See Geological Report on Wisconsin, Iowa and Minnesota, pp. 50, 53, 501, etc., and 

 Table of species, etc., 631 ; aleo Explanation of Tab. 1 B 



