no. 1404. PARASITIC COPEPODS—CA.LIGIDjE— WILSON. 553 



frontal margin of the carapace, leaving- a notch where it emerged, and 

 usually a portion of the filament itself projecting from the base of the 

 notch and extending backward into the carapace to the gland. These 

 remains persist all through the adult life and are an abiding evidence 

 of the relation between chalimus and adult. 



SUMMARY. 



1. The eggs as they are extruded to the exterior in the egg tubes 

 assume a biscuit shape with the germinal area at about the center of 

 the proximal side. The embryos develop until they cover this side 

 and extend down over the edges of the biscuit, their longitudinal axes 

 being closely parallel. 



2. As the embryos develop they become pigmented, the pigment 

 varying in color and arrangement in different species, and in this way 

 affording good supplementary evidence of identity. 



3. Each egg ruptures separately, and the membranes of the egg 

 tube split just opposite the embryos, allowing the latter to wriggle 

 out, and leaving behind the membranous framework of the egg tubes 

 the same size and shape as before and still attached to the female, but 

 empty. 



•f. The nauplii swim to the surface and toward the light as soon as 

 they are free. Each has a typical nauplius form, ovate or elliptical in 

 outline, strongly flattened dorso-ventrally, and with three pairs of 

 appendages representing the first and second antemue and the man- 

 dibles. 



5. The first antennae are uniramous and terminate in two long plu- 

 mose seta?. The second antennas and mandibles are biramous, the 

 exopod four-jointed, each joint bearing a long plumose seta, the 

 endopod with a single joint terminating in two similar setae. Near the 

 posterior end of the body is a pair of spatula-shaped balancers. 



6. The first moult occurs during the first thirty-six hours, usually 

 at night; the nauplius emerges with its body considerably elongated 

 and with the evident beginnings of segmentation posteriorly. The 

 appendages remain unchanged. 



7. The second moult occurs during the second thirty-six hours, also 

 at night; the nauplius emerges radically changed. The median eye 

 has disappeared, and instead we find a pair of e} T es fused on the median 

 line, as in the adult. The carapace is more clearly defined, and covers 

 about two-thirds oC the body; there are two free thoracic segments, 

 each bearing the rudiments of swimming legs, followed by a third 

 segment with even more rudimentary appendages, and this in turn by 

 the fused genital segment and abdomen, the latter terminated by a 

 pair of blunt anal papillae armed with seta*. For appendages this 

 larva possesses first and second antennae, first and second maxilhe, 



