140 The Ottawa Naturalist. | October 



L'Anse k la Barbe, in the Bale des Chaleurs, and in Division 4 of 

 the Anticosti group of Anticosti. 



Among these fossils from the Equan River there are seven 

 specimens that obviously belong to the genus Trimerella. This 

 g-enus was constituted by E. Billings in 1862 for the reception of 

 two remarkable species of fossil brachiopoda from the Guelph 

 formation ot Ontario. The specimens upon which it was based 

 are a few imperfect casts of the interior of one or both valves, 

 from Gait, Hespeler and Elora, and even now specimens with any 

 considerable portion of the test preserved are quit-e rare in 

 Canada. The genus was recognized in the Silurian rocks of 

 Gothland by Lindstrom in 1867, also in those of Ohio by Meek in 

 187 1, and it has been closely studied by many palaeontologists. 

 In 1872 Davidson and King made it the type of a new family, 

 which they called the Trimerellidae, and in 1874 published a com- 

 prehensive illustrated memoir thereon in the Quarterly Journal of 

 the Geological Society of London. This family belongs to that 

 large section or Order of the brachiopoda known as the Inarticu- 

 lata, in which the hinge line has no interlocking teeth, and is 

 believed to be most nearly related to the Lingulidae on the one 

 hand and to the Obolidae on the other. The latest detailed in- 

 formation in regard to the Trimerellidce is contained on pages 30 

 to 46 of Volume viii, Part i, of the Paleontology of the State of 

 New York, by Professor James Hal! and Dr. John M. Clarke, 

 published in 1892. 



As now understood, the family consists of four genera, viz., 

 Trimerella^ Monomorella, Rhinobolw: and Dinobohis. In Canada 

 Dinoholus has been found only in the Black River limestone, and 

 the other three genera only in the Guelph formation. Up to the 

 present date seven species of Trimerella have been described, five 

 from the Silurian rocks of North America, and two from rocks of 

 similar age in the islands of Gothland and Faro in Sweden. 

 Specimens of each of the five North American species have been 

 found in the Guelph formation of Ontario, and the types of four 

 of them are from that formation and province. The seven speci- 

 mens from the Equan River that are referable to this genus seem 

 to indicate or represent two species that are distinct from any of 



