Stone Lilies of the Trenton Limestone. 53 



fhe neighbourhood of the City of Ottawa, — two from the quarries at Beau- 

 port, near Quebec, and four or five from other localities. It is probable 

 that the Trenton-limestone will, in course of time, furnish seventy or 

 eighty species within this Province. 



The most important Genus, or the one that contains the greatest number 

 of species, in the rocks of this section of the country, has been known since 

 the appearance of the work last referred to, under the name of Glyptocrinus , 

 .so called on account of the sculptured surface of the specimens first dis- 

 fovered. Many of the strata of limestone appear to consist principally of 

 the plates and broken columns of several species of this very prolific family. 



The body or cup of Glyptocrinus consists of five pelvic plates — fi^i pri- 

 mary rays, with three plates in each, and ten secondaries, with from two to 

 five plates each, the number for these latter not being the same in all the 

 {species. The spaces between the rays are filled with interradial plates to 

 the upper extremities of the secondary rays. In each of those spaces, at 

 the bottom, there is one large interradial ; upon each of these, in four of the 

 spaces, there are two, and in the fifth two or three. Above this point, they 

 become smaller and more numerous. The free arms are long, and either 

 single or more or less branched. The column is round and composed of 

 two kinds of joints, those of one kind are much thicker and broader than 

 those of the other, and as they project upon all sides they produce the an- 

 nulatcd appearance seen in the figure below. Some of these columns were 

 probably six feet in length. One of them, in our possession, is 47 inches 

 long, and has evidently lost a piece from each end. Each species of Glyp- 

 tocrinus has a dilTerent form of column from that of all the other species, but 

 still they are all of the same structure, or composed of the thin and thick 

 joints. They are the moniliform or necklace-shaped columns of pateoutolo- 

 •gists, so called from their resemblance to a string of beads. The plates of 

 the calcarous covering of Glyptocrinus are generally flat and thin. In some 

 species they are smooth ; in others variously ornamented by ridges, radiating 

 across them, or by elevated borders round their margins. These superficial 

 markings of the plates together, with the form of the joints, the column 

 iind the mode of branching of the arms, are the specific characters. All the 

 specimens of the same species have the same external markings, but all the 

 individuals of the genus have the same structure of the cup, from the base 

 up to the top of the primary rays. 



Fig. 3 represents a fragment of limestone, with two of those encrinites 

 partly imbedded in its surface. It was found in a quarry on the shore of 

 Brigham's Lake, a small sheet of water in the To-wiiship of Hull, near the 

 mouth of the river Gatineau. In a space of about four yards in length by 

 three in breadth, upon the surface of a thin stratum of the rock, there were 

 about twenty crinoids, all of this species, with portions of their columns still 

 attached. Besides these, there were a number of separate columns lying 

 upon the same surface, several of them crossing each other, and all more or 

 less curved. It appears that on this spot, while it was covered by the ocean, 

 a small group of crinoids had grown, and that owing to some dostructiva 



