LORICATA. 



283 



The Phyllosoma of Palinurus is to be distinguished from that of Scyllarus by 

 certain features, some of which have already been pointed out. In the youngest 

 Phyllosoma of Palinurus, the second antenna is shorter than the first (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 Phyllosoma of Palinurus, and so is the 

 advanced development of the maxillipedes and ambulatory limbs in the 



Fi. 131. Older Phyllosoma of Palinurus (after GLAUS). 7, liver ; mf", second 

 mf", third inaxillipede ; p 1 , p^, p 3 , p 4 , p 5 , the five ambulatory limbs. 



laxillipedt 



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

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

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

 uncertainty be referred to the different genera of the lamellicorn Loricata 

 (Scyllarus, Thenus, Ibacus, Paribacus, etc., RICHTERS, 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 Phyllosoma 

 Duperryi Guerin, which belongs to MILNE-EDWARDS' group of the " Phyllosomes 



