98 



Part III. — Eighteenth Annual Report 



III. — Dissection of Male Crabs Caught in Creels. 



S. indicates soft crab ; H. hard crab. 



o 



2 A 





c 



o 









1898-K 

 Monti 



s 

 to 



Conditi 



Sizes in Inches. 



Vae Deferens. 



SpermatophoreB. 



May. 



G 



H. 



6 : 6 T % : 6 T 5 B : 6f„ : 6U : 6|. 



Large ; swollen ; white. 



Present. 



June. 



3 



H. 



4& : 5 T V : 5f. 







July. 



14 



H. 



4 : 4^ : 4& : 4§ : 4* :4ft : 4f : 5^ :5| : 

 5£ . 5£ : 5g : 6£ : 6 r V 







„ 



4 



H. 



3& : 4 : 4 T V : 4 f \. 



Pale ; white. 



" 





5 



H. 



3 : 3| : 3}§ : 3} : 4$. 



Pale. 





Aug. 



9 

 5 

 5 

 4 



S. 

 S. 



s. 

 s. 



4^ :4J :4f :5 T V :5A : 5J : 5f : 5if :7J. 

 3 T V : 4^ : 4| : 4}f : 5}. 

 3f* : 3ft : 4 : 4} : 4,\. 

 3| :3ft :3}§ : 4 J. 



Swollen ; white. 



White. 



Pale. 



» 

 ,, 



Not made out. 





3 



H. 





Swollen. 



Present. 



Sept. 



670 



H. 



uver 4^. 



Large ; swollen ; white. 





Oct. 



6 

 6 



s. 



H. 



5& 5| : 5| : 5| : 5H : 6H- 



m : 4}£ (No. 973) : 5£ (No. 897) : 5* : 

 5g : 5f. 



Swollen ; white. 

 Large ; swollen ; white. 



» 







H. 



4f (JN 0. 831 ) . 4{^ (JN 0. 994) : 4f % (IN 0. 88b). 



Pale ; white. 









H. 



3Ht : 3}R : 43 : 4-& : 5^ : 5^ : f>\ : 5f : 

 : 5§ (No. 673) : 5f . 



Large ; swollen ; wbite. 



" 



" 



2 



H.{ 





Thin ; pale ; white. 





Nov. 



5 



s. 



5f (No. 1115) : 5f| (No. 1135) : b\ : 6f 

 (No. 1084) : 6ft. 



Thin ; white. 







9 



H. 



4f (No. 835) : 4f# : 5 (No. 1039) : 5| : 5£ 

 (No. 1136) : 5J : 5£ (No. 1082) : b\% : 

 7 (No. 1172). 



Moderate thickness ; 

 white. 







1 



H. 



6J. 



Large ; swollen ; white. 







1 



H.J 



4Jf (No. 1000). 



Small ; pale. 



» 



Dec. 



1 



s. 



3f. 



Pale. 







4 



H. 



4jf (No. 1140) : 5f : 5| (No. 1064) : 6f 

 (No. 1111). 



Large ; swollen ; white. 







2 



H. 



5 A (No. 1104) : 5 T 7 -g (No. 1166). 



Small ; white. 







4 



H. 



34 : 3H : 3& : 4. 









8 



H. 



31 : 3g : 3f : 3£ : 3£ : 3f : Z\\ : 3}f. 



Small ; pale. 







2 



H. 



3 T % : 3|. 



Pale. 



Not made out. 



* Hard crab. t Vas deferens crowded with spermatophores. % Just become hard. 



External Sexual Characters. 



The male may be readily distinguished from the female crab by three 

 external characters. These are, in the order of their importance :— 

 (1) The presence of intromittent organs on the first and second abdominal 

 segments of the male, and, in the female, of four pairs of swimmerets on 

 the abdomen, and the two vulvae on the fourth thoracic segment ; (2) the 

 shape of the abdomen, which in the male is narrow, in the female 

 broad ; (3) the form of the carapace, which in the female is more convex 



