282 DlCTYOSPONOID^E. 



PLATE XLII. 

 CERATODICTYA, gen. nov. 



Page 117. 

 (8«e Plates XXII, XLI, XLni.) 



OeE.\I0DICTTA CABPENTEBIA^fA, Sp. nOV. 



Page 117. 

 (See Plate XLIII.) 



Figure 1. A finely preserved sjjecimen of a part of the sponge, having an 

 apparently normal curvature, and showing the character of the 

 reticulum and the duplicate annulations. 

 Chemung group. Near Ischua, New York. 



PRISMODICTYA, gen. nov. 



Page 79. 

 (See Plates XVH, XVlil, XIX, XX, XXI, XXVII, XXXIII, XXXIV, XXXV, XXXVT, XLI, LV.) 



Prismodictya telttm, Hall (sp.). 



Page 80. 

 (See Plates XVII and XXXV.) 



Figure 2. A small cigar-shaped individual shoAving a twisted or spiral mode 

 of growth. 

 Chemung group. Welhville, New YorJc. 



Pkismodictya cercidea, sp. nov. 



Page !W. 

 (See Plat« XX.) 



Figure 3. A flattened but entire example, sho^^■ing the expansion of the 

 sponge above the middle and the low nodes on the prism-angles. 

 Chemung group. WellwilU, Neio York. 



DICTYOSPONGIA, gen. nov. 



Page 72. 

 (Se« Plates XIV, XV, XVI, XXVII, XXXIII, XXXAa, XXXVIII, XLI, XLIV, XL\1, LV, LVI, LXI.) 



Dictyospongia sir^a, sp. nov. 



Page 75. 



Figures 4, 5. Two individuals showing the size and general form of the 

 species, one of them (figure 4) retaining the long tuft of basal 

 spicules. 

 Lower Chemung group. Cotton hiU, near Avoca, Neio York. 



Prismodictya cf. prismatica. Hall. 

 Figure 6. Part of a cup which may prove to belong to this species. 

 Lower Chemung group. Italy, Yates county, Nero York. 



