Plate 1. First-Stage liOBSTER. 



Figure 1. Left, first and second antennae from below, M^40. In the first- 

 stage lobster the first antennse project hardly to the end of the rostrum. The 

 endopodite which later form the smaller inner branches, have just commenced to 

 bud off on the inner side of the outer member, or exopodite, and is furnished with 

 one seta. The exopodite has at its tip several smaller setae. The second an- 

 tennae at this stage are composed of two parts: a broad leaf-like outer branch, 

 the exopodite, whose inner margin is curved and furnished with a variable number 

 of feathered setae, and whose tip has one sharp spine ; also a more slender inner 

 part, the endopodite, which bears setae chiefly at the tip, but whose divisions into 

 antennae segments has not yet occurred. 



Figure 2. Bight second antennae from above, M = 50. Description as above. 



