PLATE 4. 



Fig. 26. Upper part of seizing jaw of Sagitta enflata. X 1130. 



Fig. 27. Upper part of seizing jaw of Sagitta Jiexaptera. Old jaw. 

 X 1130. 



Fig. 28. Upper part of seizing jaw of Sagitta hexaptcra. Young jaw. 

 X 1130. 



Fig. 29. Upper part of seizing jaw of Sagitta lyra. X 1130. 



Fig. 30. Upper part of seizing jaw of Sagitta serratodentata. X 1130. 



Fig. 31. Upper part of seizing jaw of Sagitta bipunctata. Old jaw. 

 X 1130. 



Fig. 32. Upper part of seizing jaw of Sagitta bipunctata. Young jaw. 

 X 1130. 



Fig. 33. Upper part of seizing jaw of Sagitta planlto)iis. X 1130. 



Fig. 34. Upper part of seizing jaw of Sagitta neglecta. X 1130. 



Fig. 35. Upper part of seizing jaw of Eiikrohma liamata. X 1130. 



Fig. 36. Upper part of seizing jaw of Eukrohnia subtilis. X 1130. 



Fig. 37. Upper part of seizing jaw of Spadella draco. X 1130. 



Fig. 38. Upper part of seizing jaw of Sagitta elegans. X 1130. 



ABBREVIATIONS. 



b. pt. — base of point. p. can. — pulp canal. 



bk. sh. — back of shaft. pt. — point. 



cr. — crest. ser. — serrations. 



eg. sh. — edge of shaft. s«'. — swollen place in pulp. 



p. — pulp. t. sh. — top of shaft. 



[178] 



