no. 1480. SCHTZOPOD CRUSTACEANS— ORTMANN. 49 



appressed to the back of the abdomen, and reaches as far as the middle 

 of the telson. The rostrum is very" long, longer than the carapace. It 

 is bent down and appressed toward the ventral side, and directed back- 

 ward. Neither rostrum nor dorsal spine show any serrations. 



All appendages, except the eyes, are closely appressed to the ven- 

 tral face of the body and are directed backward. In my figure they 

 are not drawn in the natural position, but are slightly spread out and 

 removed from the ventral side in order to show them more distinctly. 



The eyes are well developed and of yellowish color. All other 

 appendages resemble more or less those of the adult form, with the 

 general exception that the hairs and bristles are absent or less devel- 

 oped and with the following special exceptions (compare Sars's 

 Plate VIII): 



The marginal spine of the antennal scale is longer than the laminar 

 part and has no serrations on the outer margin. 



The second maxilla possesses an additional joint at the end of the 

 distal portion of the endognath (called "palp" by Sars, see his fig. 7 P 

 on Plate VIII). This joint is very small, only about one-fifth as long as 

 the preceding joint (the terminal one in the adult) and less than half 

 as wide. (In the-adult it seems to be fused with the penultimate joint, 

 as is indicated by the shape of this joint in Sars's figure.) The u pig- 

 mented basal protuberance " (or luminous organ) is indicated in the 

 larva. 



The maxilliped resembles Sars's figure (Plate VIII, fig. 8) and also has 

 no exopodite, as is characteristic of the second group of the genus 

 (excepting G. gracilis), but it is more slender, the third of the five 

 free joints being not enlarged and about half as wide as in the adult 

 G. longispina. 



The gills are vestigial and less complex than in the adults. 



The tip of the telson has not yet assumed the shape of the adult form 

 (see Plate II, fig. 2b). It is not terminated by two strongly-curved 

 spines forming an "almost semilunar" projection, but is terminated 

 by a cordiform or, rather, reniform plate, which carries on each side 

 a larger and a smaller spine and is finely denticulate at the posterior 

 border. The marginal spines of the telson are more uniform than in 

 the adult form, only a few smaller spines being found between the 

 larger ones. 



It appears that these larvae come very near to the adult form, only 

 the carapace remaining what might be called "embryonal" in shape. 

 From the presence of a marsupial pouch it was to be expected that 

 the young reach a high stage of development before being set free 

 and dismissed from the mother's protection. As it happens this has 

 been fully confirmed by the present study, the }^oung contained in 

 the pouch of the mother having passed completely through all embry- 



Proc. N. M. vol. xxxi— 06 4 



