Allopeas clavulinum (Potiez & Michaud, 1838)
“This shell makes, so to speak, a transition from Bul. clavulus to Bul. oryza, which is the shortest; its last whorl is proportionately larger than that of its two congeners, its summit is more obtuse and it is a little more ventricose.” (Pilsbry, 1906 after Potiez & Michaud, 1838)
“The species has been so variously identified, that references to the literature would foe useless and misleading. The species I take to be clavulinum is related to johanninum and to mauritianum, but it is smaller than the latter, with the spire less swollen above. The specimens figured are from Mauritius (pl. 23, figs. 21, 22).” (Pilsbry, 1906)
“Cette coquille fait pur ainsi dire le passage du Bul. clavulus au Bul. oryza qui est le plus court; son dernier tour est proportionnellement plus grand que celni de ses deux congénères, son sommet est plus obtus, et il est un peu plus ventru.” (Potiez & Michaud, 1838)
“Opeas clavulinum differs from O. gracile in being not so slender, with more impressed whorls and a more obtuse apex. Due to the close resemblance of the two species, O. clavulinum is not always duly recognised. Therefore the records in literature ought to be critically considered.” (Benthem-Jutting, 1952)
“In Mousson collection at Zurich there are two shells from Sarawak, Borneo, classified as Stenogyra achatina Pfr., collected by Doria in 1869. In my opinion these shells are Opeas clavulinum (Pot. & Mich.) and herewith the occurrence of this species in Borneo is definitely ascertained. At present I cannot enter into the question whether or not the other samples collected by Doria and described by Issel (Moll. Borneensi, 1874, p. 51) as Stenogyra achatinacea really belong to this species. For the Fauna of Java the problem is of no further interest.” (Benthem-Jutting, 1952)
Potiez & Michaud (1838) original descriptions on Bulimus clavulinus – “Bul. Testâ turritâ, fragili, vitreâ, nitidâ, diaphanâ; anfractibus senis, convexis, ultimo majore; aperturâ ovatâ supernè et ad sinistram angulosâ; peristomate simplici, acuto; apice obtuso.”
Pfeiffer (1855) original descriptions on Bulimus singaporensis – “B. testa imperforata, ovato-turrita, tenuissima, laevigata, pellucida, pallide cornea, lineis fusculis longitudinalibus nonnullisque spiralibus infra medium anfractus ultimi notata; spira regulariter conica, apice acutissima; anfr. 9 convexiusculis, ultimo 1/3 longitudinis paulo superante, rotundato; apertura vix obliqua, ovali; perist. simplice, recto, margine columellari subcalloso, adnato.”
Pilsbry (1906) translations on Potiez & Michaud’s Opeas clavulinus – “Shell turrited, fragile, glassy, shining, diaphanous; whorls 6, convex, the last larger; aperture ovate above and to the left angular; peristome simple, acute; apex obtuse.”
Pilsbry (1906) descriptions on Opeas clavulinum – “The shell is openly perforate, pale yellowish-corneous; striate, but the sculpture is decidedly weaker than in 0. gracile; glossy. The sides slope almost straightly, but are a little convex near the obtuse apex. The upper part of the spire is wider than in 0. gracile. Whorls 7, moderately convex; the suture slightly irregular but not crenulate. Aperture about as in 0. gracile. Compared with 0. johanninum, this species is smaller, less conic, and less deeply-grooved longitudinally.”
Benthem-Jutting (1852) descriptions on Opeas clavulinum – “Shell moderately to high turreted, with several whorls. Yellowish white or corneous, highly polished and transparent. Vertical striation fine; spiral striae very weak. Whorls 6 to 8 ½, regularly increasing in size. Well rounded, hence the suture is distinct. Not marginated, but sometimes delicately crenulated by the extremities of the vertical striae. Last whorl about one-third of the entire shell-length. Top obtuse, more obtuse than in Opeas gracile. Base rounded. Umbilicus more or less entirely closed by the columellar reflection. Aperture vertical, or little oblique. Irregularly oval, pointed above, rounded below. Peristome not continuous, sharp, not thickened or reflected along the free margin, slightly so along the columellar margin.”
Bulimus clavulinus – “Longueur 8 mill” (Potiez & Michaud, 1838); Bulimus singaporensis – “Long. 8, diam. 4½ mill.” (Pfeiffer, 1855); Opeas clavulinus – “Length 8 mm.” (Pilsbry, 1906 after Potiez & Michaud, 1838); Opeas clavulinum – “Length 7, diam. 2.4 mm.” (Pilsbry, 1906); Opeas javanicum “Die erwachsene Schale von Pauh besitzt 7 Umgänge und miβt: Höhe 9.6 mm; Durchm 3.6 mm. Das Singkarak-Stück hat 6 ¾ Umgange und miβt: Höhe 8.6 mm; Durchm. 3.4 mm. Das letztere Exemplar lieβ im Uterus 6 Eier erkennen.” Rensch, 1934); Opeas gracile – “Die Schalen von Noilmina sind reltiv groβ. Die 4 gröβten Exemplare messen: Höhe 9.3-10.8 mm, Durchm. 3.0-3.2 mm.” (Rensch, 1935); Opeas clavulinum – “Dimensions: height 10 to 12 mm, width 3 ½ to 4 mm, height of aperture 3 ½ to 4 mm.” (Benthem-Jutting, 1952)
Type locality – Bulimus clavulinus “L’ile Bourbon” (Potiez & Michaud, 1838); Bulimus singaporensis “Singapore” (Pfeiffer, 1855)
Other localities – Opeas clavulinum “Mahe, Seychelles” leg. A. Brauer (Pilsbry, 1906); Opeas javanicum “Mittelsumatra: Hohe von Pauh bei Fort de Kock & See von Singkarak” (Rensch, 1934); Allopeas clavulinum “Kelantan; Gua Panjang, (4°48’00”N, 102°00’00”E)” (Davison & Kiew, 1990); “Kelantan; Gua Gagak, (4°46’00”N, 101°58’20”E)” (Davison & Kiew, 1990); “Kelantan; Gua Sendok Utara, (5°11’40”N, 102°02’05”E)” (Davison & Kiew, 1990); “Kelantan; Gua Henderik, (4°45’20”N, 101°46’40”E)” (Davison & Kiew, 1990); “Kelantan; Gunung Reng, (54°3’00”N, 101°44’55”E)” (Davison & Kiew, 1990); “Kelantan; Gua Setir, (5°40’00”N, 101°55’40”E)” (Davison & Kiew, 1990); “Kelantan; Gua Ikan, (5°21’10”N, 102°01’40”E)” (Davison & Kiew, 1990); “Kelantan; Batu Tampah, (4°51’25”N, 101°57’20”E)” (Davison & Kiew, 1990); “Kelantan; Gua Jaya, (5°05’40”N, 101°46’25”E)” (Davison & Kiew, 1990); “Kelantan; Gua Palda, (5°06’45”N, 101°45’30”E)” (Davison & Kiew, 1990); “Kelantan; Batu Pulau Raba, (5°04’15”N, 101°55’35”E)” (Davison & Kiew, 1990)
Distributions: “Japan, China, Sumatra, Java, Lombok, Flores, Adenare, Sumba, Ambon, Ternate (Hawai, Mauritius: wahrscheinlich verschleppi).” (Rensch, 1934); “Sunda-Inseln bekannt von Bali, Lombok, Flores, Sumba, Savu, Timor, Adenare, Solor.” (Rensch, 1935); “Originally recorded from the Bourbon Islands, but nowadays in Mauritius, Seychelles, japan, Hawaiian Islands, probably spread by human agency. In Malay Archipelago established in Sumatra, Borneo, Java, Bali, Celebes and Ambon. Probably also in other islands, but Opeas clavulinum is not always recognised as a separate species and often mixed with O. gracile.” (Benthem-Jutting, 1952)
“Living on the ground, under stones, fallen leaves, grass and among earth. Occurring from 300 to 2000 m altitude.” (Benthem-Jutting, 1952)