PALEONTOLOGIC CONTRIBUTIONS 87 



2 Serpulites lumbricoides nov. 

 Plate 29, figure 3 



Tube very gradually tapering to a width of 2.5 mm or more ; 

 of very broadly elliptic section. Surface shows regular straight 

 transverse impressed lines, along which the test overlaps slightly 

 forward, giving it a segmented appearance ; and irregular wrinkles. 

 Both the lines and wrinkles do not extend upon the lateral thick- 

 enings. Test very glossy and yellowish to black in color, the speci- 

 men resembling much the dried test of an angleworm. 



This species differs from S . d i s s o 1 u t u s in its much smaller 

 rate of growth (1 in 25 as against about 1 in 14 in the other species) 

 and the greater width attained, for our specimen appears from its 

 slow rate of growth to have nearly attained its mature condition. 

 It grows from a width of 1.7 mm to one of 2.5 mm in a length of 

 20 mm. 



Horizon and locality. Trenton limestone at Trenton Falls. 



3 Serpulites angustifolius (Hall) 



This species with its adhesion disks has been fully described by 

 Hall and the writer in the publications cited before. It is especially 

 characterized by its rapid expansion. It has been found in the 

 upper Canajoharie shale about Dolgeville and in the Mohawk 

 valley attached in great numbers to cephalopod and gastropod 

 shells. It does not seem to have grown to very great length, the 

 longest specimen observed measuring about 40 mm. Its rate of 

 expansion is from an initial width of 1 mm to 6f mm in the length 

 given. 



4 Serpulites crassimarginalis nov. 



Plate 29, figures 4 and 4a 



Large, transverse, elliptic cone of very gradual expansion attain- 

 ing a length of 95 mm, and a width of 6 mm. The marginal welts 

 are very thick (1.3 mm wide) ; the basal disk apparently small. 

 The smaller rate of expansion and the thick marginal welts are 

 the principal characters distinguishing this species from Serpu- 

 lites angustifolius. 



This species occurs in the Utica shale at Holland Patent, N. Y., 

 and other localities. 



5 Serpulites gracilis nov. 

 Plate 28, figures 5-8 



Cones extremely slender, attaining a length of 70 mm but a width 

 of only 2.3 mm. Test thin and marginal welts distinct only in the 

 proximal portion. Basal disk small. 



