40 GUIDE TO LOCALITIES. 



B. Middle Cambrian beds. 



BRAINTREE QUARRY. 



Boute.—By train, from Old Colony station, Kneeland street, to Quincy, 

 seven and three-fourths miles; single fare, $.15. Thence by electrics 

 or bicycle to Quincy point, turning south just before reaching the bridge 

 across the Weymouth Fore river. Follow the road, crossing Ruggles 

 creek, for one mile to Hayward's creek. Follow right bank of Hay- 

 ward's creek to quarry. 



This is the famous Braintree trilobite quarry, from which the 

 first authentic Massachusetts trilobite was obtained, in 1856 ; 

 although the species had been described as early as 1834 from a 

 specimen of unknown source. 1 The trilobite is Paradoxides har- 

 lani Green ; and since the finding of the first specimen, numerous 

 more or less perfect individuals have been obtained, the best of 

 which are now in the collection of the Boston Society of Natural 

 History. Fragments of this species are common on the loose 

 blocks in the quarry, but good specimens can be obtained only 

 by blasting. Two other trilobites have been found here, Agraulus 

 quadrangularis Whitfield, with a smooth, more or less squarely 

 truncated glabella, and Ptychoparia rogersi Walcott, with the gla- 

 bella rounded anteriorly and the frontal limb with a well marked 

 marginal rim. Two pteropods are known, Hyolithes shaleri Wal- 

 cott, and Hyolithes ? hay wardens is Grabau. Both are rare. The 

 former is recognized by its large size, rapidly tapering form, 

 and biconvex transverse section; while the latter is characterized 

 by a slender, slightly curving form, and nearly circular cross- 

 section. Parmophorella aoadica Matthew (=Discina acadica 

 Hartt) also has been found in these argillites, but so far only poor 

 specimens have been obtained. 



C. Upper Cumbrian beds. 



Quartzite pebbles containing Scolithes and Lingula not infre- 

 quently are found on the south shore and on Martha's Vineyard. 

 They are derived commonly from the Carbonic conglomerates. 



DEVONIC SERIES. 



These rocks, though probably well represented in eastern 

 Massachusetts, nevertheless have been found to contain fossils 

 in only one locality, in Franklin county. 



1 This specimen is now in the collection of the Boston Society of Natural History. 



