THE AMERICAN LOBSTER. 249 



Fig. 184. Profile view of masticatory stomach of male lobster 7.5 inches long. Nearly ready to molt, 

 showing gastrolith in place in the wall of stomach. For drawings of the gastrolith as it 

 appears when it is dissected out and separates into its constituent spicules, see tig. 165, 

 plate 42. Two-thirds natural size. 



Plates 45a and 45&. 



Fig. 185. Molted shell of lobster shown in fig. 186. No. 1, table 24. This represents the size of the 



lobster before the molt. Length 5J inches. Natural size. 

 Fig. 186. The soft lobster, shortly after the shell shown in fig. 185 was cast off. Length, 61 inches. 



Natural size. These drawings show the average increase in size which is effected by a 



single molt 'see Chapter III). 



Plate 46. 



Fig. 187. Left cheliped of lobster, from below, showing budding and repetition of parts in propodus or 



sixth joint. 

 Fig. 188. Same as fig. 187, seen from above. Both figures from photographs, and both natural size. 



Plate 47. 



Fig. 189. Part of right crushing-chela of female lobster, 11 inches long, seen from above, showing 



budding of dactyl. Woods Hole, Massachusetts, July 13, 1894. Two-thirds natural size. 

 Fig. 190. Propodus of left crushing-claw, from below. This and figs. 191-196 are from specimens in 



Peabody Academy of Science, Salem, Massachusetts, all from adult lobsters. Two-thirds 



natural size. 

 Fig. 191. Left crushing-claw, seen from above. Outgrowth from dactyl in horizontal plane ; dactyl 



closes under propodus. Two-thirds natural size. 

 Fig. 192. Left crushing-chela, from above. Secondary dactyl bent downward slightly; no teeth; 



dactyl laterally compressed. S, spine of dactyl in primary symmetry; S', spine of dactyl 



in secondary symmetry. This supernumerary appendage probably represents two dactyls 



fused together. Two-thirds natural size. 

 Fig. 193. Right cutting-chela, from below. Fingers bent up; dactyls articulate at joint with pro- 

 podus ; primary dactyl and one of the adjacent secondary dactyl united. S, supernumerary 



dactyl in primary symmetry. Two-thirds natural size. 

 Fig. 194. Dactyl of left cutting-claw, seen from below. It is bent horizontally upon itself, into an 



angle of about 80°, this being probably due to irregular growth in the regeneration of a 



lost part. Two-thirds natural size. 

 Fig. 195. Chela of second or third pereiopod, from below, showing two supernumerary dactyls. 



Two-thirds natural size. 

 Fig. 196. Right dactyl of cutting-chela, seen from outer side. Bifurcating branches bear teeth, which 



are not, however, apposed. Two-thirds natural size. 



Plate 48. 



Fig. 197. Deformed right cutting-claw. Accessory appendage bent downward from horizontal plane 

 about 50°. The small terminal joint of the superadded part probably represents two 

 dactyls fused together. S, spine of dactyl in primary symmetry; S>, spine of dactyl in 

 secondary symmetry. Two-thirds natural size. 



Fig. 198. Right cutting-claw. Propodus apparently deformed by the irregular growth produced in 

 the regeneration of a lost part. Two-thirds natural size. 



Fig. 199. Double monster of first larva of lobster. Raised at Fish Commiosion station, Woods Hole, 

 Massachusetts, by Professor J. A. Ryder; seen from above. 13 times natural size. 



Fig. 200. Double monster of first larva of lobster, from Professor J. A. Ryder. Fusion of the organs at 

 the anterior extremity has been carried to such a degree that the compound eyes are now 

 represented by a small median spot of pigment. 13 times natural size. 



Plate 49. 



Fig. 201. Gland-cell from tegumental gland of second maxilla. Macerated in Be"la Haller's fluid for 



several days, and stained in methyl green. 733 times natural size. 

 Fig. 202. Gland-cell from same preparation as fig. 201. 733 times natural size. 



