1 



INTRODUCTION. 



t urcs wove obsevved swimming about as before. To 

 vender the inattev, if possible, still move cevtain, some 

 of the ova weve opened, and the embvyos extvacted; but 

 shortly aftenvavds I had the pleasuve of witnessing, be- 

 neath the micvoscope, the natuval buvsting and escape 

 of one pvecisely similav in fovni to those found so abun- 

 Fi s- c - dandy in the water. Thus, 



then, theve is no doubt 

 that these grotesque- 

 looking cveatuves ave the 

 young of the Carcinus 

 Manas; but how diffe- 

 vent they ave fvom the 

 adult need havdly be 

 pointed out any fuvthev 

 than by vefevving to tlie 

 fig. (c}. When they fivst 

 escape they vavely exceed 

 half a line in length. The 

 body is ovoid, the dovsal shield lavge and inflated, on its 

 uppev edge and about the middle is a long spine, cuvved 

 posteriovly and vathev longev than the diameter of the 

 body, though it varies in length in different specimens ; 

 it is hollow, and the blood may be seen circulating 

 through it. The uppev portion of the body is sap- 

 gveen, and the lower semi-transparent. The eyes ave 

 lavge, sessile, and situated in front, and the circum- 

 ference of the pupil marked with radiating lines. The 

 lower margin of the shield is waved, and at its posterior 

 and lateral margin, is a pair of natatory feet. The tail 

 is extended, longer than the diameter of the shield, 

 and is composed of five equal annulations, beside the 



