Wiegmannia gigas Collinge, 1901
“This fine species is the largest I have seen of the genus. The visceral mass is considerably larger than in either of the two following species, and the keel on the mantle is only very feeble developed.” (Collinge, 1901)
Collinge (1901) original descriptions on Wiegmannia gigas – “Animal greyish-brown, with few blackish blotches on the sides of the body posteriorly. Head and tentacles dark blue, lateral grooves prominent, median line of rugae well marked. Mantle finely spotted with black; posteriorly does not cover the visceral mass; has a thin shell-border and faint trace of a keel. Extremity of foot truncate. Posterior portion of dorsum bluntly keeled. Extremity of foot truncate. Posterior portion of dorsum bluntly keeled. Rugae ill defined, fairly large laterally. Sulci blackish. Caudal mucous pore a longitudinal vertical slit extending to the foot-sole. Peripodial groove distinct. Foot-fringe same colour as the body with faint black lineoles. Foot-sole yellowish-brown, with two faint chocolate-coloured bands between median and lateral planes; lateral planes marked by tranverse lines, median plane papillated.”
“The vestibule is a large, spacious cavity, into which the penis opens on the right side. This latter organ is very characteristic of the genus, differing in its length, peculiar form, and the presence of a diverticulum, from the same organ in Parmarion and Microparmarion. In the present species it is folded upon itself at a distance of about one-third from its proximal end; then forming a loop-like portion it enters the distal third; at the distal end of the loop-like portion, a short retractor muscle is inserted, and at the commencement of the distal third there is a short diverticulum. I looked carefully for any trace of calcareous granules here, but did not succed in finding any. Gradually tapering to a fine tube, the penis now passes imperceptibly into the long vas deferens, which joins the prostatic portion of the common duct on its left side (Pl. II. fig. 27). The receptaculum seminis is a large, pear-shaped, sessile sac, and has, in this species, a short retractor muscle attached to its free end (Pl. II. fig. 27). The vagina is a short tubular cavity with the small opening of the receptaculum seminis on the right side – when looked at from the anterior end-and the larger opening of the free-oviduct on the left. This latter organ is rather more than three times the length of the vagina; it is coiled upon itself, making a single turn, and then passes into the larger, richly convoluted oviducal portion of the common duct, which is also folded upon itself toward the anterior end. A similar condition obtains in all the three new species here described. The albumen gland is large, as is also the flattened, elongated hermaphrodite gland, which latter has a comparatively short and slightly convoluted duct. The dart-gland is a large and conspicuous organ, lying on the left ventral side. It has the usual fold at about its middle, and a short retractor muscle at its distal end (Pl. II. fig. 27). The dart is smaller than in either of the two following species; it measures 3.7 millim. in length, is slightly curved, and the body, externally, is not differentiated from the head, which is a solid calcareous tip.” (Collinge, 1901)
Wiegmannia gigas – “Length (in alcohol) 50 millim., foot-sole 10 millim. Shell dark amber-coloured, membranaceous, faint trace of apical whorl.” (Collinge, 1901)
Type locality – “Kuching, N. W. Borneo” (Collinge, 1901)