Hemiplecta floweri Smith, 1899
“This very fine species is distinguished by the wide rich brown perspective umbilicus, the orbicular form, and peculiar oblique subwrinkly striation. The coloration is also distinctive. The sutural line itself is white. This is margined on the outside with a dark rufous line half a millimetre to a millimetre in width. The body-whorl slightly above the middle exhibits a pale zone 2-3 mm. in breadth, which is bordered beneath with a dark-red band of about the same width. Beneath this there is a broad dark-olive zone, which gradually becomes lighther upon the base of the whorl until the rich brown of the umbilicus is reached. A feature exhibited by this and some other species (e.g. H. humphreysiana, Lea; H. densa, Ad. & Reeve) is the presence of one or more linear indentations upon the last whorl within the umbilical opening near the columellar margin.” (E. A. Smith, 1898)
E. A. Smith (1898) original descriptions on Hemiplecta floweri – “Testa orbicularis, late perspective umbilicata, flavo-olivacea, supra peripheriam zona pallida infra rufo marginata cincta, infra zonam saturate olivaceo tincta, circa umbilicum rufo-fusca; spira brevissime conica, ad apicem obtuse; anfractus 7, sublente accrescentes, convexiusculi, linea suturali alba rufo marginata sejuncti, superiors 3-4 fere leaves, caeteri lineis incrementi obliquis arcuatis sculpti, irregulariter tenuiter et confertim oblique striati, ultimus antice vix descendens, ad peripheriam rotundatus, infra concentrice irregulariter tenuiter striatus; aperture obliqua, latissime lunata, intus caerulescens; peristoma simplex, haud incrassatum, marginibus laeviter conniventibus, columellari ad insertionem vix expanso aut reflexo.”
“The living animal is apparently black, or grey-black, and, judging from the wrinkled condition of its edge in the spirit specimen, the foot probably spreads out thin and flat when the animal is in motion, as seen, to name a striking instance, in the large Eucochlias ochthoplax, Bens., the foot of which is often extended till it forms a thin oval disc, giving great holding power. The peripodial fringe is very marked, streaked with pale lines on the black ground; the parallel grooves so distinctive in many genera of the Zonitidae are not apparent. The sole of the foot is not divided; the whole surface is wrinkled by contraction. This in life would probably be quite smooth, while the mucous gland would apparently be broad and open, without any very marked overhanging lobe. The mucous gland does not extend to the sole of the foot. There is a right Shell-lobe, situated at a short distance below the upper inner angle of the aperture; also a well-developed left shell lobe, tongue-shaped, and given off from the narrow peristomatic edge. The left neck-lobe is divided into two very distinct and widely separated portions. At the lower angle of the aperture, and corresponding with the dark band of colour round the umbilical region, there occurs an expansion of the shell-lobe, which we may term the ‘umbilical, or columellar lobe,’ and the breadth of this is indicated by one or more shallow grooves on the surface of the shell itself. There is also (as noted by Mr. Smith) a single, shallow, but well-marked groove following the suture about 6 mm. from it. This is also indicated on the edge of the shell-lobe by slight notching or folding. The inside surface of the mantle zone resting against the umbilical margin was, I noticed, of a red-brown colour, corresponding to the coloration of the shell within the umbilicus. But it seems to me more likely that this was a stain extracted by the alcohol from the shell after death, rather than the remnant, in this part of the animal, of the colouring matter which produces the band. The shell-muscle is strengthened by a peculiar, flattened, disc-like expansion, which I have not observed before in any other species. Close to this, internally, are situated the attachments of the retractor muscles of the buccal mass, amatorial organ, etc.” (Godwin-Austen, 1901)
“The salivary glands are disposed in two thin, flat masses, connected with each other and covering the stomach. The buccal maw is short and flat on the basal side. The jaw has a large central projection. The radula has the formulas - 83 : 18 : 1 : 18 : 83 and 101 : 1 : 101. The central tooth and 18 admedian teeth are straight-sided; the next 34 lateral teeth- that is, up to the 52nd- are aculeate; the 31 uncini are bicuspid.” (Godwin-Austen, 1901)
“Genitalia - The amatorial organ, which is proportionately of great length (75 mm.), tapers to the retractor muscle. The spermatheca is long, broad at its base, gradually dwindling to a well-defined connective muscle attached to the oviduct. The male organ, which tapers from the generative aperture backward, is bent on itself, the two portions being attached about midway by muscular tissue. It then leads up to the short kalk sac, and the vas-deferens enters it at the side. Above the bend a caecum is given off, which presents one single coil, and to the rounded apex of this the retractor muscle is attached. We have here some interesting details illustrative of the variation met with in these animals, and serving to distinguish this species from other large forms. Compared with the type species of Hemiplecta, the male organ is similar, save that in H. humphreysiana there is no caecum, whereas in this Perak species a caecum, approaching in form that of Macrochlamys, is present. The spermatheca of Hemiplecta humphreysiana is rather short, and pear-shaped, not long, and narrowing to an attachment muscle. There is some difference in the relative position of the right shell-lobe in the two species: in the Perak form it is given off at a lower point on the mantle zone, and this is also the case in some other species. The radula is of the same type in both, and if the admedians be added to the curved aculeate laterals the number is identical, viz. 70 : 1 : 70, the difference in the total number being made up in the outermost bicuspid teeth. The jaw of the Perak snail has a much larger central projection. These differences do not outweigh the similarity of the radula, and shell and dorsal lobes, and I therefore leave it, where Mr. E. A. Smith placed it, in Hemiplecta.” (Godwin-Austen, 1901)
Hemiplecta floweri – “Diam. Maj. 64, min. 51 mm.; alt. 38 mm.” (E. A. Smith, 1898)
Type locality – “Maxwell’s Hill, Larut, Perak” (E. A. Smith. 1898)