A STUDY IN MORPHOLOGY. 133 



Fig. 34. A Protozoea, yg-^oth inch long, and a little older than the one shown in fig. 27. 

 os. (Esophagus. 

 pp. Annl pigment spots. 

 (Other letters as in fig. 27.) 



PLATE 4. 



Fig. 35. Side view of another larva at the stage shown in fig. 34. 

 ga. Cerebral ganglia. 



s. Stomach. 



sg. Shell gland. 



h. Heart, 

 Fig. 3 5 A. Surface view of the area of attachment of the oesophageal muscles of the 



same larva. 

 Fig. 36. Second antenna of the same specimen. 



I. Basal joint. 



ex. Exopodite. 



en. Endopodite. 



Fig. 37. Mandible, at same stage, seen from below. 

 Fig. 38. First maxilla of left side at same stage. 



1 and 2. The two cutting joints of the basal portion. 



ex. Exopodite. 



en. Endopodite. 

 Fig. 39. Left-second maxilla at same stage. 



b. Basal portion. 



en. Endopodite. 



sc. Scaphognathite. 

 Fig. 40. Left-first rnaxilliped at same stage. 



ex. Exopodite. 



en. Endopodite. 

 Fig. 41. Left-second maxilliped at same stage. 



ex. Exopodite. 



en. Endopodite. 



Fig. 42. Ventral view of the same larva after the next moult and TooTJ^ 1 ' inc ^ l n g- 

 Fig. 42A. Outline of the anterior end of fig. 42, more enlarged. 



b. Basal joints of appendages. 



ex. Exopodites. 



en. Endopodites. 



ftc. Scaphognathite. 



