140 Discoveries in the St. John Group. 



gulella, and two new species of Stenotheca. Two worm-casts 

 and new species of bivalve crustaceans also come in at this horizon. 

 Among the trilobites also there are new species ; the Agnosti 

 have four ; Microdiscus exhibits a new form closely allied to M. 

 punctatus, Salter. Among the Ptychopariae some species now 

 appear for the first time, and Solenopleura has a representative. 

 A Paradoxides with shortened eyelobes has left abundant frag- 

 ments in these measures ; it is a species which, by its pleural spines, 

 pygidium and hypostome, is allied to P. tesseni of Europe. 



This new fauna consists largely of forms similar to those of the 

 Menevian group, and is chiefly remarkable for the great abun- 

 dance of Pteropods, Microdisci and Agnosti, and for the presence 

 of a Paradoxides with shortened eyelobes. So far as they are at 

 present known, each of the successive sub-faunas has an indivi- 

 duality of its own ; that in band b contains forms the most remark- 

 able for novelty ; band c is notable for the variety of species it con- 

 tains, and band d for the abundance of individuals of many of the 

 species. The beds of the band b may be said to have been de- 

 posited on a sandy shore, those of c on a muddy shore, and those 

 of d in deeper and more tranquil waters. Volcanic action in the 

 vicinity of the St. John basin seems to have been dormant during 

 the time when the beds of band a. were laid down, but awoke into 

 activity during the period when the strata of b were deposited, 

 and gradually died away while the olive-grey mud beds of c were 

 formed. The time when these successive faunas were making 

 their way into the St. John basin was a period of decreasing vol- 

 canic action and of gradual subsidence in that area. 



In concluding this article, I quote a letter of Prof. Alpheus 

 Hyatt of Boston, well known for his researches among the Ceph- 

 alopods and Sponges, which relates to one of the new forms 

 noticed in the preceding paper. Prof. Hyatt had very kindly 

 offered to advise me in reference to difficult points connected with 

 the fossils of the St. John group, and I therefore availed myself 

 of this opportunity to place before him the various specimens of 

 pteropodous shells bearing upon the possible early connection of 

 the pteropods with the cephalopods. Unfortunately, the letter 

 giving the details of his examination of these fossils has been lost 

 in transmission, but the general results of the investigation are 

 given in the summary quoted below from a later letter. By way 



