LARVAE .OF DECAPOD CRUSTACEA 



409 



development of the abdomen to the second stage in the Discovery specimens. There is 

 therefore no exact comparison possible between the development of this Pmmliriis and 

 either of the Loricata of which the development is known. All that is certain is that there 

 must be several earlier stages still to be found. The first stage oi P.japontcus, according 



"4 MM 



Fig. 18. Panulirus A, iS mm. St. 297. 



to the figure of Nakazawa, measures 1-3 mm., and unless the rate of growth is remark- 

 ably great, it is necessary to suppose that there are many as five unknown stages, or 

 eleven in all. I have accepted this number provisionally. The actual number of stages 

 may seem a matter of small importance, but it must have some bearing upon the length 

 of larval life and consequently on the possibilities of distribution. It is very disappoint- 

 ing that in this, as in the other cases, the earliest stages are not represented in the material 

 and speculation has to take the place of observation. 



