MUSEUM OF COMPARATIVE ZOOLOGY. 329 
Plate III. 
Fourth larval stage ; cephalo-thorax, from below. 
The same; penultimate thoracic appendage. 
The same; last thoracic appendage, 
Fifth larval stage; cephalo-thorax viewed from below. sp, spinous 
process of second pair of antenne, 
The same; anterior part of the carapace. 
The same; fifth abdominal somite, viewed from the side. 
The same; labrum (20) and mandibles (111). 
The same ; second maxilla, 
The same ; natatory branch of the tenth pair of appendages. 
The same; abdominal appendage of the first pair. 
The same; abdominal appendage of the second pair (those of the 
third and fourth pairs have the same form), 
The same; abdominal appendage of the fifth pair. 
The same ; telson and swimmerets, 
Sixth larval stage, one moult after the fifth larval stage ; antenna of 
the second pair; sp, spinous process, 
The same; first cheliped. 
The same ; second cheliped. 
The same; one of the abdominal appendages, 
The same; telson and swimmerets, 
Plate ۰ 
(Norn. Figs. 9-14 are from drawings by Mr. A. Agassiz.] 
Sixth larval stage, two moults after the fifth larval stage, lateral view. 
The same; second antenna; sp, spinous process, 
The same; cheliped with its external, natatory branch (r c). 
The same ; first abdominal appendage, 
The same ; second abdominal appendage. 
The same; posterior margin of the telson, 
Sixth larval stage, three moults after the fifth larval stage ; anterior 
end of first antenna. 
The same ; telson and swimmeret. 
Seventh larval stage ; rostrum and eye. 
The same; second maxilliped. 
The same; third maxilliped. 
The same; chela, 
The same; rudimentary external branch (re) of thoracic legs. 
The same; posterior thoracic leg. 
Young prawn, 8 min. long, which has acquired most of the characters 
of the adult, 
Adult, third maxilliped. 
The same ; scale of second antenna, 
Fig. 
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7 
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l'ig. 
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l'ig. 
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ia 
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