406 APPENDIX. No. III. 



partly formed ; they must have mistaken the yelk, M'hich will 

 be seen in the drawing to be unusually large, for the new 

 shell. 



ExPLANATIOX OF THE PlATES. 



PLATE XIII. 



Fig. 1. The shell of the helix janthina, with the ova in its 

 camerated nidus, attached to it; magnified twice in diameter. 



Fig. 2. A portion of the nidus magnified 12 times in dia- 

 meter. 



Fig. A string of the same nidus magnified 25 times in dia- 

 meter. 



Fig. 4. Two of the same ova and one empty chamber, magni- 

 fied 50 times in diameter. 



Fig. 5. One of the same ova, and 



Fig. 6. The same slightly bruised, both magnified 50 times 

 in diameter. 



Fig. 7. A portion of the camerated nidus, in a dried state, 



belonging to the ova of a univalve from south Carolina, of the 



natural size. 



Plate XIV. 



Fig. 1. The shell of the argonauta, with the ova of the octo- 

 pus deposited in it, magnified twice in diameter. 



Fig. 2. A cluster of the same ova, as they are seen when im- 

 mersed in water, magnified 12 times in diameter. 



Fig. 3. One of the same ova with its pellicle, magnified 25 

 times in diameter. 



Fig. 4. The yelk of the egg. 



Fig. 5. A transversal section of the same. 



Fig. 6. A longitudinal section of the same. The three pre- 

 ceding figures are magnified 50 times in diameter. 



Fig. 7. A collapsed egg, as seen when taken out of the v/a- 

 ter, magnified 25 times in diameter. 



