SECONDARY SEXUAL CHARACTERS OF CRAYFISHES. 265 



was described by F. Xicholls in 1730. Another specimen has 

 been described in the Canadian Naturalist, Vol. XXXIII, Xo. 2. 



Rosseau and Desmarest described several cases in Astacns 

 Jha'iatilis of branched oviducts opening on the third and upon the 

 fourth walking legs. 



Yon Martens described three specimens of Cheraps preisii, 

 an Australian crayli-h, in which there were openings at the 1 

 of the third walkin. luit no oviduct- and no ovaries. The 



specimen- were normal male- except for this peculiarity. 



Yon Ihrii .. I dnnberg, Faxon and Hay working upon variou- 



ies of Parastacus, a genii- found in South America, found that 



then- were i ' n-tant conditions of the genital inland-, il 



ami external ^enitalia. luoc.f these conditions pointed toward 



|).irtial hermaphroditism. In -ome species there were 



Mmje uenit.il inland-, fit her -permaries or ovarie-. and tv, 



. enital iliM i- am! genital openings. Only one of the sets 

 tube- u.:- fum tioii.il. however. In other spi -ingle genital 



inland am! two sets of genital tubes existed but there were no 

 ital opening- for the non-functional tube-. In -till another 

 >pe ie- I lien- wafl n- - < \ i< ; ' ther of extra genital lube- >r .f 



extra genital opening-. The normal condition in the tir-t two 

 Mibdi\ i-inii- o| tin- v eiiu- was, therefore, one of partial herma- 



phroditism. 



1 axon [885 foiiml foul - in the genii- Cani'unii which 



\ ve some evidence of hermaphroditism. 

 One specimen of Can <{>inqu:. >w, 60 mm. loi 



had the clau 5 of 3 female, the alIominal a|)pemla.;e- of ,i female 

 ami a well-formed amuilu- but no li-male genital opening- at the 

 ba-i- of the thiid walking legs. In-teal, it had the external 



ital opening- of a male at the base of the fifth walking 1. 

 Hi i-ction deiunn-trated the pre-ence of a well-de\-elo|n-d o\,u\ 

 MI the -pecimeil \\ 'a- e\ idell 1 1\" a lelllale. 



The -ecoml i\i-e wa- al-o one of Cambarns pro pi n<i nits sanborni, 

 38 mm. loiii^. The specimen \\a- female in every n -] ept 



that the tir-t abdominal appendages were like tho-eof the m 



The third case -pecimen of Ciimbunts ^4 mm. 



Ion-, in which the external genitalia were tho-e of a female with 

 the exception of the tir-t abdominal appendage- which wi-re 



