E. 0. Hovey — Cordierite Gneiss from Connecticut. 57 



where in New England, about half of them at [Nantucket. 

 According to the assignment of synonymy and distribution in 

 Messrs. Yerrill, Smith and Harger's catalogue* six of the 

 species now extend southward to Florida, one each to the 

 Carolinas, three to New Jersey, one (common north of Cape 

 Cod), does not appear in Yineyard Sound ; in the other direc- 

 tion, three reach the Arctic ocean, one Greenland, three Labra- 

 dor, two the Gulf of St. Lawrence, three Massachusetts Bay. 

 Two remain below low- water mark, one is almost confined to 

 sandy places ; a large majority may be found in the colder 

 waters of the ocean shores as well as in the bays, etc., but 

 three prefer the sandy or muddy shores and bottoms of sounds, 

 bays and estuaries. Venus mercenaries is of this last group. 

 The apparent prominence of this species at Winthrop Head is 

 doubtless partly referable, to the solidity of its shell and the 

 consequent endurance of the same in recognizable form where 

 other shells were broken up or decayed. 



Tertiary of Southeastern Massachusetts. 



The dredging for the Cape Cod canal in Sandwich has 

 brought up fragments of bone similar to those found at Gay 

 Head. No published notice of this fact has come to the 

 writer's attention. It is to be hoped that the opportunity for 

 observation has been or will be duly utilized by some one in 

 the interests of science. 



Art. IX. — A Cordierite Gneiss from Connecticut / by E. O. 



HOYEY. 



Cordierite, or iolite, has long been known to occur at 

 Haddam, Ct., where it is found " associated with tourmaline in 

 a granitic vein in gneiss." It has also been reported as being 

 abundant in quartz in the gneiss north of Norwich, Ct., and at 

 Brimfield, Mass. No true cordierite gneiss, however, has 

 heretofore been reported from this country. A gneiss of this 

 kind was recently found by the writer in the town of Guil- 

 ford, sixteen miles east of New Haven, while in search of gar- 

 nets and vesuvianite. The outcrops begin on the western side 

 of a hill 375 ft. east of the Guilford -Durham turnpike, about 

 two and a half miles north of the railway station on the farm 

 of Richard Woodruff ; the line of ledges was traced for a 

 fifth of a mile. The general course of the ledges is N. 15° 

 TV", (true), while the strike of the bedding of the rock seems 

 to be N. 25° TV., which gives them a calculated aggregate 

 * Report upon the Invertebrate Animals of Yineyard Sound, etc., 1874. 



