4 Dr. W. G. Eidewood on a Case of 



fisli, there are regularly two pairs of genital ducts, one leading 

 from the gonad to the coxal joints of tlie third pair of legs 

 and the other to those of the fifth. In the male tlie anterior 

 duct is somewhat narrower than tlie other and does not really 

 open to the exterior, the "orifice " on the third leg not being 

 patent. In the female the posterior duct is considerably 

 thinner than ihe anterior ; it is too narrow to allow of the 

 passage of ova, and ends blindly on the coxopodite of the 

 fifth leg. There are thus vestigial oviducts in tlie male and 

 vestigial vasa dcferentia in the female. Loiinberg found in 

 the testis large bodies resembling ova, and he is inclined to 

 regard the species as exhibiting a partial structural, but not 

 functional, hermaphroditism. 



In i'amharus, a North American Astacld, Faxon* has 

 observed four cases in which external features of the two 

 sexes are combined in the same individual ; and Lonnberg f 

 speaks, with some hesitation, of rudimentary ducts passing 

 to the third legs in two males. 



In Cheraps preissii, an Australian crayfish, von Martens J 

 has descril ed three males with additional orifices on the third 

 pair of legs; tiiere were no tubes connecting tiiese openings 

 A\ilh tlie gonad. 



In the Indian deep-sea species of the family Axiidae it is 

 common to find in adult females orifices corresponding with 

 the genital orifices of the male §. 



In male specimens of a Pacific hermit-crab, Pagurus 

 deformis, supernumerary apertures on the third or ante- 

 penultimate legs seem to be regularly present |i, although 

 Borradaile •[I mentions a case in which the supernumerary 

 aperture was absent on one side of the body. 



In the lobster, Homarus vulgaris^ abnormal genitalia are 

 very rare, if one may judge from the paucity of recorded 

 cases of abnormality. Kicholls** in 1730 described a case 

 of complete hermaphroditism in a lobster, the left side of the 

 gonad being testicular, and furnished with a duct leading to 

 the last walking-leg, and the right half being ovarian, with 



* Faxon, W., Mem. Mus. Comp. Zool. x. 4 (Camb., Mass., 1885), 

 pp. 13-14. 



t L. c. pp. 349-350. 



t Von Martens, E., Sitz.-Ber. Ges. naturf. Fr. Berlin, 1870, pp. 1-2. 



§ Alcock, A., Indian Deep-sea Crustacea Decapoda Macrura and 

 Auouiala in the Indian Museum (Calcutta, 1901), p. 187. 



II Hilgendorf, F., Mon.-Ber. Ak. Wiss. Berlin, 1878, p. 818; and 

 Oriraann, A., Zool. Jahrb., Abth. Sjst. ri. 1892, p. 288. 



f Borradaile, L. A., Proc. Zool. Soc. Lend. 1898, p. 4G0. 



** Nicholls, F., Phil. Trans, xxxvi. 1730, pp. 290-294. 



