of a new Species and Variety q/* Avion. 253 



either side of the body a, narrower light brown band borders 

 the median one, and this in turn is bounded by another darlc 

 vandjke-brown band about half the breadth of the median 

 one. The sides of the body and the foot-fringe are of a light 

 brownish white, the latter being striped with faint sepia lines. 

 The sole is pale yellow. The ruga are somewhat oval and 

 flat, separated by deep sulci. The caudal gland is small and 

 inconspicuous. 



The alimentary and nervous systems agree very closely 

 with the condition found in A. empiricorum^ F^r. ; there are 

 some slight modifications, however, in the form, position, and 

 branching of the buccal nerve and a number of minor modifi- 

 cations in the muscular system, in both of which features 

 it differs from any known species. Individually, however, 

 I am not inclined to attach much importance to these. The 

 differences in the generative system are the best marked 

 and such as to at once indicate its specific identity. There is 

 a large single vestibule ; the upper portion of the receptacular 

 duct is greatly enlarged, but it cannot at all be regarded as a 

 second vestibule. The sperm-duct is a moderate-sized taper- 

 ing organ continued as the vas deferens, which is noticeable 

 on account of its length. The receptacular duct commences 

 as a much dilated tube, tapering to a small and short duct 

 which opens into' a large oval-shaped sac — the receptaculum 

 seminis. There is a large muscle attached to the distal end 

 of this organ (PL IX. fig. 2, r.s. and r.m.). The oviduct is 

 exceedingly large and usually exhibits a series of more or less 

 well-developed constrictions ; wdiere this large proximal 

 portion joins the distal portion of the free oviduct there is a 

 small flagellura, to which a muscle is attached. This muscle 

 originates from the right body-wall, posterior to the peri- 

 cardial cavity, and, as well as being attached to the oviduct, 

 is continued forwards and attached to tlie upper portion of 

 the receptacular duct. The oviduct and prostate are mucli 

 convoluted, and in all the specimens dissected were found to 

 have a position quite different to that found in any other 

 members of the genus as far as I am aware. On turning 

 back the body-wall from the left side, the large albumen- 

 gland is noticed lying over the oviduct and prostate, these in 

 turn lying over the free oviduct, sperm-duct, vas deferens, &c. 

 The albumen-gland is exceptionally large, as is also the her- 

 maphrodite gland, which is of a deep slaty-purple colour ; it 

 opens into the hermaphrodite duct, a long convoluted tube. 



It will readily be seen that A. Jlagellus differs in a number 

 of well-marked anatomical characteristics from any other 

 known species. It may, I think, be regarded as a form inter- 



Ann. d: Mtuj. N. Hist. Ser. G. Vol xii. 20 



