EOLIS. 



and larger, sending off only one large nerve into the tentacles. In E. cornata and E. Drummondi 

 the genital nerve is supplied with a small triangular ganglion at its junction with the collar. 



The eye (PL 8, fig. 3 b, and fig. 7) is situated on a small elongated process at the 

 outer side of the central ganglion immediately in front of its junction with the lateral 

 ganglion. It is composed of a thin capsule inclosing a black pigment cup, which receives 

 the optic nerve from below ; in front of the cup, and half buried in it is a spherical lens, 

 which is protected by a cornea a little in advance of it. 



The auditory capsule is placed directly behind the eye, and is attached to the central 

 ganglion. The otolithes are inclosed in two thin membranous bags, exceedingly delicate and 

 transparent. In E. papillosa (fig. 4) and E. coronata, the otolithes are small, elliptical, and 

 very numerous, but in E. aurantlaca, E. olivacea, and E. picta (fig. 6) there is only one 

 large spherical otolithe. 



The organs of generation (PL 8, fig. 2) are very voluminous, filling by far the greater 

 portion of the cavity of the body. The intromittent organ is capable of much prolongation, 

 and terminates in a fine, perforated, tapering point. In its contracted state it lies in front 

 immediately within the orifice, and behind it are the female channel, and a small orifice 

 opening on its anterior wall. The testicle (fig. 2 c) is a long convoluted tube situated in 

 front of the other parts, and is connected with the intromittent organ at one end, and at the 

 other with the oviduct. The ovarium (fig. 2 d) is very bulky, and, during the breeding 

 season, almost entirely fills the posterior portion of the cavity of the body ; it is deeply fissured 

 in the dorsal median line, and divided into transverse lobes. The oviduct (fig. 2 e) is a 

 delicate tube, receiving branches on each side from the various lobules, after which it dilates, 

 and is twice or thrice bent upon itself, before it passes into the general channel. In con- 

 nexion with the female parts is a large laminated gland (fig. 2 g, g) formed of two lateral 

 lobes, occupying the greater portion of the cavity in front of the body. It is composed of 

 two portions, an outer homogeneous, white, semi-pellucid part, and an inner and anterior part, 

 which is granular, opake, and of a pale flesh colour. The ducts of the two lobes unite and 

 form the common female channel. This gland secretes the mucus by which the mass of eggs 

 is enveloped. In addition to the parts already described there is a small globular sack 

 (fig. 2 h), which lies between the lobes of the great gland and at its posterior margin. This 

 is the purple bag of Swammerdam, and there can be little doubt that it is a true spermatheca. 

 A duct from this receptacle, having been joined by the duct of a small elliptical accessory 

 gland, is united with the oviduct after the junction of the latter with the testicle, and 

 immediately afterwards a branch of communication opens into the female channel. The duct 

 of the spermatheca is then continued on to the small orifice before mentioned immediately 

 within the common aperture. 



From an examination of the anatomy of these organs, it would appear that impregnation 

 is effected by the channel of the spermatheca, which, receiving the semen from another 

 individual, retains it till required ; but from the connexion of the testicle with the oviduct, 

 each individual would also appear to have the power of self-impregnation. The ova after 

 impregnation reach the common female channel, where they receive the gelatinous envelope 

 previous to expulsion from the body of the parent. 



