EXPLANATION OF PLATE 4. 



Fig. 1. Calyptograptus subretiformis (Spencer), p. 28. 



2. Circular frond of same. 



Fig. 3. CalyptograptusC?) radiatus (Spencer), p. 30. 



Fig. 4. Khizograptus bdlbosus (Spencer), p. 30. 



Fig. 5. ACANTHOGRAPTUS GRANTi (Spenccr), p. 31. 



Fig. 6. ACANTHOGRAPTUS PULCHER (Spencer), p. 32. 



