28 Gk 0- Sårs. 



First Calyptopis-stage. 



(Pl. 4, figs. 1, 2). 



In this stage, which immediately succeeds the Meta- 

 nauplius-stzge, the larva has a length of about 1 mm., and 

 exhibits the 2 chief divisions of the body more distinctly 

 defined, whereby the macorurous character of the larva be- 

 comes more apparent. The carapace wholly covers the 

 anterior division, and its lateral parts extend inferiorly so 

 far as almost completely to receive between them the post- 

 oral appendages, the tips of which only may at times pro- 

 ject beyond their edges. Seen laterally (see fig. 1), its 

 dorsal face appears still very strongly vaulted, with an 

 abrupt curvature in the middle. Anteriorly it terminates in 

 an obtuse projection, whereas posteriorly it appears broadly 

 truncated, forming almost a right angle above. The free 

 edges of the carapace are slightly insinuated in the region 

 of the mouth, but become boldly arcuate behind, joining the 

 posterior edge by a strong curvature. Seen dorsally (fig. 

 2), the carapace exhibits a perfectly regular elliptical form, 

 its anterior part not, as in the Metanauplius-stage, 

 abruptly expanded, but quite continuous with the posterior 

 part. The edges of this part, moreover, are perfectly smooth, 

 without the slightest traces of the peculiar radiating spinules 

 found in the Metanauplius. The posterior division of the 

 body, which in the latter stage was only indicated by a 

 very short projection, has lengthened considerably, though 

 as yet not nearly attaining the length of the anterior. 

 It is still unsegmented and slightly flattened distally, with 

 the extremity truncated, and armed with the same number 

 of spines as in the Metanauplius-stage; but these spines 

 are now considerably stronger and less unequal in length. 



