LORICATA. 



283 



The Phyllosoma of Paliiuirus is to be distinguished from that of Scj///arus hy 

 certain features, some of which have ah'eady been pointed out. In the youngest 

 Phyllosoma o{ Palinurus, the second antenna is shorter than the ih'st (Fig. 130), 

 but this condition is soon reversed (Fig. 131), and henceforth the second 

 antenna remains longer. In Scyllarus, on the other hand (Fig. 129), the second 

 antenna is always smaller than the first, and in later stages is transformed into 

 the lamellate organ. Again, the presence of a rudiment of the first pair of 

 maxillipedes is characteristic of the Pltyllosoma of Palinurus, and so is tlic 

 advanced development of the maxillipedes and ambulatory limbs in tlie 



Fin. 131. — Older Phyllosoma of Falinurns (after Glaus). I, liver; mf", sficond maxillipede; 

 mf", third iiiaxillipede ; j/i, ifi, p-', p*, V^^, tliP five aiubulatory limbs. 



youngest free stages. AVhile it is in this way not difficult to identify the 

 PhijUosoma of Palinurus, there yet remain many other Phyllosoma larvae, some 

 of which arc very remarkable forms, which can only conjecturally and with 

 uncertainty be referred to the different genera of the lamellicorn Loricata 

 (Scyllarus, Thenus, Ibacus, Parihacus, etc., Richtek.s, No. 146). Among these 

 last, Haswell (No. 131) has described a Phyllosoma probably belonging to 

 Ibacus. This author considers it to be a further ontogenetic stage of PhijUosoma 

 Duperryi Guerin, which belongs to Milne- Edwards' group of the " Phyllosomes 



