A new Species of Nectonemertes. 349 



scarcely visible in another. From surface view one might readily 

 suppose that they are cephalic glands or organs of special sense, 

 but sections leave no doubt whatever that they are the reproductive 

 organs. No other generative glands exist in the body, a very careful 

 scrutiny of the region behind the cirri showing that between the 

 lobes of the intestine organs of this character do not exist. Joubin 

 states that in JS. grimaldii ''Entre les rameaux de l'intestin on peut 

 voir des amas un peu plus opaques qui me paraissent être des 

 glandes genitales" but since sections were not studied this statement 

 is not conclusive, and in the light of our studies it is more than 

 likely that the masses he observes are of some other character. 



All of our specimens are males and the reproductive glands 

 throughout are of the same structure and in the same stage of 

 development, so that a description of one applies with equal force 

 to the others. It is worth}- of note that, as Joubin states, some of 

 the more anterior organs are '"plus développés" than those posterior, 

 but this applies chiefly to the size of the organ for although smaller 

 and perhaps of later origin the posterior ones have essentially the 

 same features as those of larger size. In every case, whether large 

 or small, a duct leads to a distinct opening through the body wall. 

 As usual each gland is situated in the parenchyma between the 

 branches of the intestine and the body musculature, but as is indicated 

 in Fig. 3 they do not occupy spaces between the coeca as is generally 

 the case with other nemerteans, being grouped compactly into a 

 ventral cluster between the level of the brain and the base of the 

 cirri. Generally speaking, each testis is spherical or somewhat 

 elliptical in form and communicates by means of a short duct with 

 the exterior, in some cases opening along the sides of the body and 

 in other examples far down on the ventral surface. 



The internal lining epithelium in the main section of the organ 

 is exceedingly thin and delicate and only rarely one may detect its 

 elongated darkly staining nuclei. More exteriorly especially in the 

 terminal section of the duct the cells become higher, the nuclei 

 more globular and readily distinguishable. Immediately within the 

 lining epithelium sex cells in various stages of development fill the 

 cavity (Fig. 17). Among these it is not possible to clearly distinguish 

 spermatogonia, though here and there nuclei of larger size may 

 belong to such. Spermatocytes on the other hand are very numerous, 

 and are characterized b}^ spherical nuclei in which the chromatin 

 is abundant and often in a well defined spireme stage, and much 



