PLATE XIX a. 



LlCHAS (CONOLICHAS) BlGSBYI (?). 

 Page 80. 

 Fig. I. A very large pygidium, drawn from a gutta-percha mould of the internal surface. One of the 

 terminal spines in the specimen has been broken. This form of pygidium was formerly refer- 

 red to the species Liehas pustulosus; but as the cephalon of that species is now known to have 

 been accompanied by the form of pygidium represented on plate 19, fig. 8, this is referred with 

 some hesitation to the species Liehas Bigsbyi, Hall. 



Lower Helderberg group. Schoharie, Schoharie count//. 



LlCHAS (CONOLICHAS) ErIOPIS. 



Page 78. 



Fig, 2. The intra-sutural portion of a cephalon, natural size, retaining the right palpebrum and a portion 



of the crust. 

 Fig. 3. The same, enlarged to two diameters. 



Fig. 4. The same, viewed from the front, showing the comparative elevation of the glabellar lobes. Simi- 

 larly enlarged. 

 Fig. 5. The same, viewed in profile. Similarly enlarged. 



Corniferous limestone. Schoharie, Schoharie county. 

 Fig. ti. A fragment of a smaller cephalon, enlarged to two diameters. 



Corniferous limestone. Schoharie, Schoharie county. 

 Fig. 7. The right movable cheek, enlarged to two diameters. 



Corniferous limestone. Canandaigua, Ontario county. 

 Fig. S. Another specimen of the right cheek, somewhat distorted ; enlarged to two diameters. This and 

 the preceding figures are drawn from gutta-percha casts of natural moulds in decomposed chert. 

 Corniferous limestone. Canandaigua, Ontario county. 

 Fig. it. A pygidium, showing the general proportions and the broken bases of the axial and pleural spines. 

 Enlarged to two diameters. 

 The marginal spines have been drawn with disproportionate lengths, the first pair being much too 

 short, the second ami third pairs not long enough and the terminal pair too long. For the cor- 

 rect representation of these spines, see fig. 15. 



Corniferous limestone. Schoharie, Schoharie county. 

 Fig. 10. An imperfect pygidium, natural size. 



Corniferous limestone. Schoharie, Schoharie county. 

 Fig. 11. An imperfect pygidium, showing the internal surface. 



Corniferous limestone. Schoharie, Schoharie county. 

 Pig. 12. A fragment of a very large pygidium . 



Upper Helderberg limestone. Williamsville, Erie county. 

 Pit,'. 13. A pygidium, showing the axial spine, and the length of the pleural and marginal spines. The 



original is an internal cast in decomposed chert. Enlarged to two diameters. 

 Fig. 15. A restoration of the pygidium. drawn from the preceding specimen, showing the normal character 



of the axial, pleural ami marginal spines. 

 Fig. 16. Profile view of the same, showing the leugth of the axial spine. 



Corniferous limestone. Canandaigua, Ontario county. 



LlCHAS (CONOLICHAS) HISPIDUS. 

 Page 77. 

 Pig. 14. A pygidium, natural size, showing the aspinose surface and the short marginal spines. 

 Fig. 17. The same, enlarged to two diameters. The larger tubercles upon the pleural annulations do not 

 represent the bases of spines. 



Schoharie grit. Schoharie, Schoharie county. 

 Fig. 18. An imperfect pygidium, natural size, drawn from a cast in decomposed chert. 

 Corniferous limestone. LeRoy, ffenesce county. 



