STRUCTURE OF THE CHONDRACANTHUS LOPHII. 73 



joined by a wider tube, the cement-preparing gland (Kitt-organ), which extends 

 for some distance forwards. It was traced almost to the neck ; but its exact 

 mode of termination anteriorly could not be satisfactorily ascertained. It lies 

 close to the lateral margin of the thorax, but does not pass into the lappets 

 (fig. 2, h). In the anastomosing branches of the ovary, numerous ova are 

 situated, either in single or double rows. In the great majority of our speci- 

 mens, a long and somewhat spirally twisted string of ova extends backwards 

 from the genital aperture on each side. The ova are contained in a tough, homo- 

 geneous substance, Avhich not only gives to each ovum a specific investment, but 

 forms for the whole a common continuous envelope. It appears to constitute a 

 distinct membranous tube, subdivided into numerous spaces for the ova, but it 

 is probably formed of the secretion of the cement gland, which gives to each 

 ovum a distinct investment as it passes out of the genital orifice, so that, as the 

 number of extruded ova increases, the length of the string necessarily increases. 

 By it they are kept in connection with the body of the female as long as is neces- 

 sary for their due development. The ova are crowded together in these strings so 

 as to form, not one, but several spirally arranged rows. 



Male. — Very minute. Not more than ^V^h of an inch in length, and is, com- 

 pared with the size of female, a mere speck (fig. 14). It is parasitic on the female, 

 and is connected by a pair of hooks to the posterior end of the body, close to the 

 genital orifice. Like the former observers, we have never found more than one 

 male attached to each female. In only one case, recorded by Kroyer, have two 

 males been met with on a single female. The place on the body of the female 

 which marks the point of attachment to each other of the sexes, possesses a peculiar 

 structure, which has not been pointed out in any of the former descriptions of the 

 animal. This structure consistsof a papillary projection from the anterior margin 

 of the ventral aspect of the proximal segment of the abdomen (fig. 8, r). In its 

 shape it is very like an intestinal villus, and its surface is covered by elongated, 

 columnar, epithelium-like structures, which, when highly magnified, present in 

 their interior an appearance somewhat difficult to interpret ; under some con- 

 ditions, looking like a nucleus, under others, like a central cavity (fig. 11). , The 

 structure of this projection is thus materially different from the ordinary chitinic 

 investment of the female, and offers a substance, softer than it, in which the 

 hooks of the male are embedded. One may conceive, also, that it is through it 

 that the male draws its supply of nutriment. The presence of a nipple-like 

 structure in relation to each genital orifice, would lead one to infer that the 

 male may be connected to either side of the body of the female ; and it is probable 

 that he possesses the power of changing his position from one side to the other, 

 so as to impregnate both sets of ova. 



The male is elongated in shape, much broader anteriorly than posteriorly. 



