Such an intimate connection exists in the invertebrate 

 faima of the Silurian Strata of Xorth America, England and 

 Scandinavia, that from the occurrence of any particular group 

 of invertebrate organisms in the rocks of this period in any 

 one of these countries, we may confidently expect that similar 

 or very closely allied forms will also be raet with in the same 

 strata in the other two areas. This belief induced me, two 

 years since, to pay a visit to the Isle of Gotland, with the 

 view of ascertaining if there existed in the undisturbed Silu- 

 rian strata of that island, so renowned for the exceeding rich- 

 ness and perfect preservation of its fossil Corals, Crustacea 

 and Brachiopoda, any of those minute remains of Annelids, 

 which I had discovered in the Silurian rocks of Canada and 

 England. My hopes of finding similar fossils in Gotland were 

 confirmed by the fact, which I have mentioned in my paper 

 on the Annelid Jaws of Canada [Quart. Jour. Geol. Soc. Vol. 

 35 p. 370] that an undoubted example of these minute bodies 

 had been figured by Pander from the Silurian rocks of the 

 Island of Oesel [Monogr. d. foss. Fische des Sil. Systems des 

 Russ. -Balt. Gouvernements p. 72 Pl. 4, f. 16 a, b, c, d.] and 

 they were realized, when on visiting Prof. G. Lindström at 

 Stockholm, I was shown some shale from Wisby in which 

 fragments of Annelid Jaws were clearly exposed. Further 

 than this, Prof. Lindström communicated to me the noteworthy 

 fact that his predecessor, the late Prof. Angelin, had discover- 

 ed some of these fossils in Gotland, many years since, and, 

 what is still more important, that he recognised their true 

 characters. In a letter to Prof. Lindström dated Wisby, June 

 19, 1864, Angelin remarks as foUows: »De små haklika par- 

 tierna som du i stor mängd trakterade mig med från Vatten- 

 fallet vid Wisby, och som, för öfrigt, anträffas öfverallt på 

 Gotland — äro lemningar af Annelider — käkar deraf och 

 hudbeklädnad.» »The small hooked fragments from the 



