15i; 



MILAX SOWERBII. 



Fig. 169.— Internal shell 

 of Milax sowerbii^ X 4. 



(Chriscch\irch, Hants S., 

 Mr. C. Ashford) 



of the nigse, thereby defining them very distinctly, and giving a reticulate appear- 

 ance when tlio animal is contracted ; kekl of aii amber colour, very distinct and 

 prominent on the back, the caudal end scarcely prominent, and hardly differing in 

 colour from the general aspect of the body ; SHIELD about one-third the total length 

 of the animal, granularly wiinUlcd; tlie protuberant, somewhat lenticular area 

 extends to the posterior margin, is rounded on the left-side, but angulated on 

 tlie right, and defined by a distinct suhms, which is further accentuated by the 

 closer aggregation therein of the black specks, which are sprinkled over the whole 

 shield, but more especially upon the posterior mid-dorsal portion overlapping the 

 keel ; TENTACLES thick, short, conical, and black, their granulate surface finely 

 sprinkled with ochre-yellow, apices swollen and somewhat oval with black eye 

 specks ; NECK with the usual jiaired dorsal grooves, which on tlie forehead bifurcate 

 and form four pale parallel lines ; foot ]i;ile, and tripartite, the median area 

 broadest and slightly darker posteriorly owing to its transluceney ; FOOT-MARGIN 

 smooth, yellowish-white, bounded by a distinct groove above, upon which rests a 

 single row of tubercles, which are separated from the sides of tlie body by a deep 

 channel. Mucus thick and viscous, and usually colourless, but when the animal is 

 irritated or soahled may become of an orange tint; when tlie slime is removed the 

 animal loses much of its yellow colour, which is thus partially due to its slime. 



Shell oblong-oval, glistening white in colour, with a somewhat iridescent lustre 

 in parts, usually slightly convex on the upper 

 side, and in young shells correspondingly 

 concave beneath, but often flat or slightly 

 convex and somewhat irregular in more 

 aged s]ieciinens; APEX or nucleus prominent, 

 nearly median, and sub-terminal in the 

 y(jiing but becoming more centrally placed 

 as maturitj' advances ; the concentric LINES 

 OF fiROWTH variable, but sometimes very 

 distinct and somewhat rugged and yellowish on the upper side. 



Length, 5 mill. ; breadth, 3 mill. 



Internally, the nerve-king has the inferior ganglia intimately fused to- 

 gether ; the siipra-cesophageal ganglia are 

 large and elongately triangular with thickish \ j 



commissures ; the HEART, KIDNEV, and ;:fM_ i— 

 LUN<: cavity have the same general locative 

 relations as in the field-slugs ; the heart 

 is as usual on the left front of the kidney, 

 and the AORTA runs for a tolerable distance 

 before dividing, as in Limri.c friims ; the 

 kidney, however, is not a roundish sac, but 

 is in two sections, one extending forward in tlie usual way, the other being a long 

 ])ointed lobe which extends over towards the right on tlie lung floor, beneath the 

 ureter and the gut ; the URETER is slender throughout its course. 



The REPRODUCTIVE ORGANS open exteriorly beneath the anterior margin of the 

 mantle, about midway between the pulmonary aperture and the base of the right 

 ommalophore ; the OVOTESTIS is generally concealed within the lobes of the diges- 

 tive gland, the acini are whitish, large, globular, and rather loose, the ducts 

 combining to form the main stem near the centre of the mass; DUCT rather long, 

 first portion slender and straight, becoming thick and convoluted as it approaches 

 the small, curved, and clavate \esicula semin.vli.s; albumen gland niany-lobed 

 and anilier coloured; ovispkkmatoduct firmly united and strongly twisted; 

 OVIDUCT rather s(dld, buff or llesh colour, and very thick and diHicult, to unfold; 

 FHEH OVIDUCT as long as the spermatheca and its duct, cylindrical and narrow, receiv- 

 ing at its h.isi' the numerous delicate ducts from the multitude of anastomosing 

 tubular glands, which constitute the vestibular prostate; SPEKJI DUCT broad, 

 well-develoiied, milk-white or liulf; \-.\s DEEEKKNs long, entering near apex of 

 epiphallus; the male oigun is suinioiiiiteil by a very slcnit, tliiek-walled, and 

 muscular epii'IIAI.i.us, is aniiiilarly riilged internally, abruptly flexed and sep.arated 

 from the iieiiis-sheath by a conspicuous siiliincter iunscle, demited internally bv a 

 ring of white prominiTice ami exteriorly by a luised ring; the PENIS SIIK.VTH is 

 narrow ami cylindrical with thiniiisli walls aiid int. riial longitudinal ridges; it opens 

 into the atrniiii or vestibule at the side lielow the opening (if the stem of the spernia- 

 thera, thesARcoiiELUM or stiiimlatory organ beinga small bent horn at the opening 

 of tln^ pcniis sheath into the atrium ; immeiliately above the sphincter a short stout 

 RETRACTOii IS allixed to the convex side of the epiphallus; it arises from the dorsum 



Fig. 170. — Nerve 

 centres of M. S07verbii 

 (greatly enlarged). 



