PLATE XXIV-Continued. 
Phaethonides CYCLURUS. 
Page 137. 
See Plate 25. 
Fig-. 26. A fragment of the cephalon, showing the lateral furrows of the glabella a little too strongly. 
Enlarged to three diameters. 
Fig. 26a. Outline profile of the same. 
Lower Helderberg group. Near 'Glarltsville, Albany county. 
Fig. 27. A pygidium, drawn from a gutta-pei-cha impression of the internal surface. The axial row of 
tubercles should be repi-esented as duplicate at the fifth annulation, as in fig. 28. Enlarged to 
three diameters. 
Lower Heldei-berg grouji. Near Clarksville, Albany county. 
Fig. 28. Another pygidium retaining the crust and showing the character of the dorsal surface. Enlarged 
to three diametei-s. 
Lower Helderberg group. Near Clarksville, Albany county. 
Phaethonides varicella. 
Page 135. 
Fig. 29. The intra-sutural portion of a cephalon, showing the tubercled and punctate surface. Philarged 
to three diameters. 
Fig. 29a. Outline profile of the same, showing the depressed frontal area and elevated margin. 
Corniferous limestone. Canandaigua, Ontario county. 
Fig. 30. An imperfect cephalon, drawn from a natural cast of the internal surface. Enlarged to three 
diameters. 
Fig. 30a. Outline pi-ofile of the same. 
Corniferous limestone. Canandaigua, Ontario ccnmity. 
Fig. 31. A pygidium, drawn from a natural cast of the internal sui-face. Enlarged to thi-ee dianietei-s. 
Corniferous limestone. Canandaigua, Ontario county. 
Phaethonides GEMMiEus. 
Page 136. 
Fig. 32. A iiygidium, showing the characteristic ornamentation. Enlarged to two diameters. 
Hamilton group. Canandaigua, Ontario county. 
. Fig. 33. Another pygidium. The axial node on the posterior margin is made too distinct in the tlrawing. 
Enlarged to two diameters. 
Hamilton gi-oup. Eighteen-mile Creek, Erie county. 
Fig. 34. A fragment, showing seven segments of the thorax. Enlarged to two diameters. 
Hamilton group. Canandaigua Lake. 
Fig. 35. A pygidium, drawn from a gutta-pei-cha impression of the internal surface which retains the 
doublure, showing the strongly punctate character of the surface between the ribs. Enlarged 
to three diameters. 
Corniferous limestone. Canandaigua, Ontario county. 
Fig. 36. A small pygidium in which the marginal tubercles are unusually conspicuous and become spini- 
form. Enlarged to two diameters. 
Corniferous limestone. Canandaigua, Ontario county. 
