Dyakia hugonis (Pfeiffer, 1863)
“Noch höher und mit noch mehr abgesetzten Windungen als die vorige, sehr nahe den höheren Formen der folgenden.” (Martens, 1867)
“The anatomy of Hemiplecta humphreysiana Lea, from Singapore, the type of the genus, which I have examined and alluded to before, differs widely from that of H. hugonis.” (Godwin-Austen, 1891)
Pfeiffer (1863) original descriptions on Helix hugonis – “Testa sinistrorsa, clause perforata, turbinata, solida, undique conferte et subargute granulatostriata, superne fuscula; spira conoidea, vertice obtusulo; anfr. 8, lente accrescentes, convexiusculi, supra suturam flavescentes, ultimus compresse carinatus, infra carinam inflatus, castaneus; aperture obliqua, irregulariter angulato-lunaris, intus margaritacea; peristome subsimplex, margine supero brevi, basali perarcuato, versus perforationem submcrassato et leviter dilalato.”
Bonnet (1864) original descriptions on Helix sinistra - “Coquille semi-globuleuse, légèrement aplatie et assez obtuse, à très-petit ombilic; pourvue d'une carène plus ou moins aiguë, peu saillante; test assez mince, peu luisant, finement chagriné sur les tours do spire et plus fortement sur la face ombilicale; d'une couleur châtaigne foncée rougeâtre sur la partie inférieure de la carène et beaucoup plus Claire et légèrement carminée vers le sommet de la coquille; cette teinte se modifie en une couleur jaune clair légèrement verdâtre vers le commencement de chaque tour; cette bande diminue de largeur et finit par disparaître vers le sommet. Spire composée de sept tours légèrement arrondis, à suture assez marquée; le premier est caréné, un peu moins convexe en dessus qu'en dessous; ouverture à gauche simple, d'un brun rouge par transparence, plus large que haute, assez bâillante à sa partie inférieure et convexe à la supérieure; la carène se faisant très-bien sentir dans l'intérieur par le contraste de la couleur brune et la bande jaunâtre; face ombilicale bombée à ombilic creusé en entonnoir et très-petit; bord columeliaire presque nul et légèrement coloré de jaunâtre.”
Martens (1867) descriptions on Nanina hugonis – “Testa sinistra, angustissime perforata, conica, acute carinata, supra et infra confertim granuloso-striata, supra pallidius, infra intensius rufo-castanea, peripheria pallide flava; spira elata, conica; anfr. 7, convexi, sutura sat profunda, ultimus infra sat convexus, carina prominente, antice haud descendens; apertura parum obliqua, lunata; peristoma rectum, acutum, margine basali valde arcuato, antrorsum producto, columellari sat declivi, ad insertionem breviter reflexo.”
Laidlaw (1963) descriptions on Dyakia hugonis - “Rather depressed pyramidal, sharply keeled, suture not impressed; whorls about 7 ½; aperture lunate; lower surface more tumid than upper; striae fine, becoming more marked on later whorls; uniformly dull brown. Diam. max. 44 mm., alt. 15 mm. This description is base on a specimen in the Royal Scottish Museum labelled “metatype”, determined by Pfeiffer. Dextral individuals are occasionally found. This species is near to janus, but has a more elevated spire.”
Tryon (1886) descriptions on Nanina hugonis – “Very narrowly umbilicated, solid, closely and sharply granulate striate, light brownish; whorls 8, slowly increasing, yellowish brown above the suture, and at the acutely carinated periphery of the last whorl, below the carina chestnut-colored; aperture pearly, lip thin, simple.”
“Animal, pale ruddy colour with small black specklings. The dorsal lobes are very considerably reduced in size; they present a very small lappet-like left dorsal and a fringing right dorsal lobe, and no shell-lobes in the spirit-specimen.” (Godwin-Austen, 1891)
“The odontophore consists of numerous teeth in the rows; the laterals very minute and unicuspid; the centrals are simple, straight sided, spear-shaped teeth without cusps: (50 . 60 . 18 . 1 . 18 . 50 or 60) and (78 . 1 . 78.). the jaw is arched with a central projection.” (Godwin-Austen, 1891)
“The generative organs are interesting because they are, as regards the amatory organ, like some other forms from the same region, and present a type not yet known to exist in India. The male organ is simple, bent on itself; the amatorial organ has at the free end, a large secretory gland, made up of five separate glands; a short muscular cylindrical part comes next, armed at the lower part with a very beautiful fine calcareous dart 3.25 millim. In length; its position is at the end of a long cylindrical open sac with rugous sides, near the base of which is the spermatheca. The albumen-gland is large, but the other parts of the generative organs present nothing that differs from the usual form.” (Godwin-Austen, 1891)
Helix hugonis – “Diam. maj. 38, min. 35, alt. 21-22 mill.” (Pfeiffer, 1863); Helix sinistra - “Hauteur, 20 mill.; plus grand diamètre, 32 mill.; plus petit, 29; bouche, 16 mill. de largeur sur 6 de hauteur.” (Bonnet, 1864); Nanina hugonis – “Diam. maj. 37½, min. 33, alt. 25; apert. long. 21, lat. 15½ Mill.” (Martens, 1867); Nanina hugonis – “Diam. 38, alt. 22 mill.” (Tryon, 1886)
Type locality – Helix hugonis “In insula Labuan” leg. H. Low (Pfeiffer, 1863); Helix sinistra “Borneo” (Bonnet, 1864)
Other localities – “Trusan” and “Niah Hills” leg. A. Everett (Godwin-Austen, 1891); “Bunguran” leg. A. Everett (E. A. Smith, 1894); “Baramflufs” (Kobelt, 1897)