PALEONTOL0GIC CONTRIBUTIONS 85 



surfaces. The British author here cited defines the genus as fol- 

 lows : Tube smooth, arched, slightly calcareous, glossy ; having 

 two small, longitudinal tubes at opposite points of the circum- 

 ference, stronger than the rest of the shell, and prolonged at the 

 posterior end. Type S. longissimus. 



It is apparent that the small longitudinal tubes " at opposite 

 points of the circumference " are identical with the thickenings of 

 the extremities of the elliptical section observed by Holm and the 

 marginal welts so distinct in our compressed specimens. That the 

 substance of the test was phosphatic calcareous with a chitinoid 

 admixture in most species is shown by the strong gloss and the 

 brownish color of the tests, as well as by their good preservation in 

 shales where all calcite has been leached out. By comparing the 

 observations of Murchison, Hall, Holm and the writer, we may 

 derive the following more complete diagnosis of Serpulites : 



Tubes of elliptical transverse section, very slowly tapering, 

 irregularly curved in two planes, or straight. The two sides per- 

 fectly alike, so that a dorsal or ventral side can not be distinguished. 

 Tubes mostly thickened or strengthened at the two extremities of 

 the broad ellipse; growing from small adhesion disks by which they 

 are attached to foreign bodies. The shell, as to its chemical com- 

 position, mostly of calcium phosphate, as to color, gray violet, or 

 brownish, or even black, resembling the shell of Conularia. Septa 

 wanting. Chitinoid setae someti'mes observed within the tube near 

 the aperture. 



Of the seven species cited by Miller {op. cit., p. 521) from the 

 Paleozoic rocks of North America, we are sure that only two 

 belong to this genus, namely, Serpulites splendens Bill- 

 ings from the Chazy rocks and S. dissolutus Billings from 

 the Trenton limestones. The other species (described by Hail 

 and Dawson) do not seem to have the typical characters cited here 

 for the genus. 



The similarity in the surface sculpture and substance of the test 

 between Serpulites angustifolius (Hall) and Conu- 

 laria gracilis led us to unite the two species which are 

 associated in the Dolgeville shale in the paper cited before. While 

 this is no longer admissible, the fact remains that the points of 

 contact between the two are so many that if Serpulites can be 

 shown to have been the tube of an annelid, the probability that also 

 Conularia may belong with the Annulata becomes very great. It 

 is therefore worth while to survey briefly the relations of Conu- 

 laria to Serpulites. The surface sculpture of Conularia consists 



