Sampling the depth: New data on the Caecidae (Mollusca, Gastropoda) from northeastern Papua New Guinea Author Walter, Angelo Vannozzi Via M. L. Longo 8, 00151 Rome (Italy) ang.vannozzi@gmail.com Author Renda, Walter Via Bologna 18 / A, 87032 Amantea (CS) (Italy) w.renda1@tin.it text Zoosystema 2024 2024-06-07 46 14 327 347 journal article 299020 10.5252/zoosystema2024v46a14 b5619e29-fcbd-4ddc-9231-138300251568 1638-9387 12548683 23D972D0-F573-429C-816B-F42AFF02D0B1 Caecum inflatulum Vannozzi, 2017 ( Fig. 2M, N ) Caecum inflatulum Vannozzi, 2017: 124 , fig. 1E-L. TYPE MATERIAL . — Holotype . Philippines • lv ; Bohol Is ., Ubajan , 16 m depth ; MNHN-IM-2000-33074 . Paratypes . Philippines • 1 lv juv; Panglao Is. , Biking ; 4 m depth ; reef; MNHN-IM-2000-33075 • 4 lv , 2 sh; Balicasag Is .; 21 m depth; floor of cave with sponges; MNHN-IM-2000-33076 • 1 lv , 1 sh; Panglao Is. , Pontod Islet ; 3 m depth; sand bottom with dead coral; MNHN-IM-2000-33077 . TYPE LOCALITY . — Pacific Ocean, Philippines , Bohol Is., Ubajan, 16 m depth. MATERIAL EXAMINED. — Papua New Guinea • 1 sh (fragm); New Ireland ; KAVIENG 2014 Stn DW 4463; 2°44’S , 150°35’E ; 240- 305 m depth ; 3.IX.2014 ; MNHN . Indonesia • 1 sh; Kotok Island ; beached; 1985; coll. WR . DISTRIBUTION . — Indonesia (new record), Philippines , northeastern PNG ( Vannozzi 2017 , 2019b ). DIAGNOSIS . — Shell of average size for the genus, colourless, semitransparent and glossy. Protoconch unknown. Teleoconch tubular, slightly arched, with strong collabral rings. Early teleoconch subcylindrical. Adult shell subcylindrical, slightly arched, tapering toward the apex. Sculpture of rather well-developed rings of uneven width, vanishing in the late teleoconch. Completely smooth specimens occur. Aperture simple, slightly contracted, preceded by a slight swelling. Shallow longitudinal grooves sometimes occur. Septum protruding, convex, with a high dorsal nail-like mucro. The mucro shows a slight hump at half of its height. Animal described by Vannozzi (2019b) . Length 2 mm . REMARKS Caecum inflatulum is a rather variable species, although the shape of the septum allows easy identification. This species can only be compared with C. attenuatum de Folin, 1880 and C. chinense de Folin, 1868 , both of them showing a similar septum. However, the former shows a sculpture of very fine rings and a differently-shaped aperture, while the latter shows a more conical and smooth shell with annular microsculpture ( Albano & Pizzini 2011 ; Vannozzi 2017 ).