Euconulidae

Hyman, Isabel T. & Ponder, Winston F., 2010, A morphological phylogenetic analysis and generic revision of Australian Helicarionidae (Gastropoda: Pulmonata: Stylommatophora), and an assessment of the relationships of the family 2462, Zootaxa 2462 (1), pp. 1-148 : 105-106

Family Euconulidae

Remarks. Since Baker’s (1941a) classification of Limacoidea s. l., all authors have divided this group into Euconulinae and Microcystinae ( Hausdorf 1998; Schileyko 2002a; Solem 1966), although Hausdorf (1998) stated that Euconulinae may be paraphyletic and Schileyko (2002b) also included a third subfamily, Kaliellinae. In the current study, Euconulinae and Microcystinae did not group together, indicating that perhaps they should be treated as separate family-group taxa. The two groups also diverged in some analyses in the molecular phylogeny of Hyman et al. (2007), although only one member of Euconulidae was included. However, both the morphological and molecular results were poorly supported and not robust enough to use as a basis for this decision, so we follow previous authors in treating the two groups as subfamilies of a single family pending better data.

Based on our analysis, the key characters defining Euconulidae are as follows:

Shell rarely reduced. Genital system oviparous or ovoviviparous; bursa copulatrix inserted on vagina or penis. Stimulator usually absent; if present, vestigial, inserted on penis; epiphallic retractor caecum and flagellum absent in most taxa. Spermatophore apparently absent in some taxa or, if present, small, soft-walled.

Description. Shell present, rarely reduced, ranging in diameter from ~ 2.5 mm in Pittoconcha concinna Preston, 1913 to 20 mm in Mathewsoconcha phillipii ( Gray, 1834) . Shell shape and sculpture variable. Mantle laps absent, or only right lap present, or both laps present. Mantle lobes absent or if present, small. Sole of foot tripartite; caudal apparatus formed from curled up sole ( Muratov’s 1999 helicarionid type); caudal apparatus very small to moderately large; caudal foss horizontal slit in tail. Kidney unilobed; mantle with no visible minor blood vessels, pigmentation absent or present, mantle gland absent or present. Genital system oviparous or ovoviviparous; oviduct glandular or non-glandular. Neither carrefour nor talon embedded in albumen gland. Bursa copulatrix short or very short, inserted on vagina or penis; duct of bursa copulatrix wide, not distinguishable from bursa copulatrix (in Liardetia doliolum bursa copulatrix is short, inserted at junction of penis and post-uterine oviduct and duct of bursa copulatrix is narrow, distinguishable from bursa copulatrix). Vagina absent or if present, short. Stimulator absent, or vestiges of stimulator present as diverticulum on base of penis. Epiphallus enters penis through simple pore, rarely two fleshy lips or verge; penis internally with no sculpture, or with longitudinal or diagonal ridges or longitudinal, circular or transverse pilasters. Penial sheath present. Penis retractor muscle attached to penis or to epiphallus near penis junction. Epiphallic retractor caecum (most taxa) or present ( Liardetia doliolum ); epiphallic flagellum absent. Spermatophore small, peanutshaped, soft-walled; attached to inner wall of penis. Radula relatively long and narrow. Central tooth with small to moderately small ectocones; mesocone lanceolate. Lateral and marginal tooth fields distinguishable. Tooth rows straight.