NOTE ON A (? STOMATOPOD) METANAUPLTUS LARVA. 435 



limbs had already made their appearance. As far as the 

 development of the limbs is concerned, the stage appears to 

 correspond with that of Euphausia pel lucid a, represented 

 by MetschnikofF in the ' Zeitschrift flir Wiss. Zoolc^ie/ Bd. 

 xxi, plate 34, fig. 6. Further, it is clear from the character of 

 the eyes that we have to do with a Thoracostracan form. It is, 

 then, a Thoracostracan larva at about the metanauplius sta^-e. 



In the Cumacea the young leave the brood-pouch nearly in 

 the form of the adult. The young of the Tiiysanopoda, 

 aoiong the Schizopods (as shown by Metschnikoffi), as well, 

 probably, as those of the Decapod Pen e us (Fritz Muller 2) are 

 hatched as nauplii, while those of Lucifer (Brooks^) appear 

 as metanauplii. But in all these the paired eyes are absent in 

 the metanauplius stage, and are not fully developed until a long 

 and fully segmented abdomen has been formed. The carapace 

 is without spines in the metanauplius stage, and thou'^^h in 

 Euphausia, and also in Lucifer, spines make their appear- 

 ance in later stages, corresponding in position with those above 

 described, their shape in Euphausia and the shape of the 

 shield in both genera are markedly different. 



The remaining Thoracostracan group is the Stomatopoda. 

 In Squill a (Paul Mayer 4) and Gonodactylus (Brooks and 

 Herrick^) the eggs have been seen to hatch as A lima larvae 

 in a stage which has been compared with the Zooea sta^e of 

 Decapods. But, as was shown by Claus,^ larvcc of S tomato- 

 pods also occur in another form, the Erichthus, of which 

 stages are known prior to that at which the Aliraa larva is 



' Loc. cit. 



* " Die VerwandluiiEf der Garneelen," Erster Beitrag, 'Arch, fiir Natur- 

 geschichte,' Jahrg. 29, 1863. 



' "Lucifer: a Study iu Morpliology," 'Phil, Trans.,' vol. clxxiii, 1S82 

 p. 57. 



■» " Carcinologische Mittheilungen, IX," ' xMittheiluugen aus dem Zoo). 

 Stat, zu Neapel,' vol. ii, p. 219. 



* " Embryology and Metamorphosis of the Macroura," ' Memoirs of the 

 Nat. A.cad. of Sciences,' vol. v, p. 353. 



« " Die Metamorphose der Squilliden," ' Konig. Gesell. d. Wissenschaften 

 zu Gottingeu,' Bd. xvi, 1871. 



