Bull. U. S F. C. 1895. The American Lobster. (To (ace page 86 ) 



Plate B. 



m iv 



Cut 6. — Left eheliped of lobster seen from the dorsal side. From specimen which molted in an aquarium 

 July 13, 1891, and which is described in Chapter III, pp. 83 to 85. See No. 7, table 24. One-half nat- 

 ural size. 



The Roman numerals I-IV correspond to the planes of section illustrated in cut 7: Arabic num- 

 erals 1-7 to segments of limb, mb, area of absorption, on upper surface of third and fourth joints, 

 x, plane of fracture. 



882 mm 2 



211mm '• 



93mm s 



274mm- 



Cot 7. — I-IV represent transverse sections of chelipcd shown in cut C in the planes indi- 

 cated by corresponding immerals.ll and IV showing the natural openings at the proximal 

 ends of the sixth and first segments respectively. Ia-IVa represent the areas of the 

 respective sections expressed graphically and numerically. (The plotted areas are 

 two-thirds natural size: the numerical expressions above them refer to actual areas.) 

 At mi. cuts 6 and 7 (III), the lime salts of the shell have been absorbed, so that the 

 cuticle is capable of distention, and the area of the transverse, section is thereby 

 slightly increased. The muscles and other tissues which fill the transverse section la 

 must be drawn through an opening the size of IIii, then through one but little larger 

 than Ilia (allowing for the distention of the membrane), and finally through the small 

 ring, IV. ITri. at the base of the limb, since there is no rupture of any of these parts. 

 Drawings two-thirds natural size. 



Drawn bij F. H. Herrick, 



