Taxonomic review of tropical western Atlantic shallow water Drilliidae (Mollusca: Gastropoda: Conoidea) including descriptions of 100 new species Fallon, Phillip J. Zootaxa 2016 4090 1 1 363 6ZCLF [151,387,1124,1150] Gastropoda Drilliidae Splendrillia Animalia Neogastropoda 291 292 Mollusca species compta sp. nov.    Typematerial. Holotype12.4 x 4.8 mm, A. Bodart! March 1999(MZSP 122075); 3 paratypes: 10.2 x 4.3, 11.0 x 4.5 & 13.0 x 5.2 mm, in 20–30 m, off Rio do Fogo, Rio Grande do Norte, Brazil, local people! Apr–Sep 2008(P. Stahlschmidt coll.).   Typelocality.off N Natal, Rio Grande do Norte, Brazil, in 10– 20 m.  Range and habitat. Brazil(Rio Grande do Norte State). Reported from 10– 30 m.   Description. Shellsmall (to 13.0 mm in total length), fusiform, truncated anteriorly, glossy, with up to 8¾ convex whorls, suture appressed, last whorl approximately 59% of shell length; aperture narrowly oval; anterior canal very short. Protoconchpaucispiral, of 1¾–2 smooth, round whorls, first not immersed in second. Axial sculptureof strong rather narrow slightly opisthocline ribs with convex, shouldered ribs that run from suture-tosuture, are much reduced and arcuate in a narrow band below suture but less so on later whorls, then evanesce at anterior fasciole on body whorl; spaces between ribs about as wide as the ribs, 10–11 on the penultimate, 6–7 on body whorl to the varix. Strong growth striae are present that run obliquely over the ribs and are recurved on the whorl’s shoulder. Varixis like an enlarged rib, higher and about twice the width of adjoining ribs, but straight, not opisthocline. Spiral sculptureconsists of about 6 spiral ridges on anterior fasciole. Asseen under a dissecting microscope, very faint microscopic lines cover the shell surface. These resolve into rows of punctae in SEM images (see Pl. 141, Figs. 5–6). Sulcusindistinct, indicated only by the reduced, arcuate ribs and striae on the shoulder that mark the prior positions of the anal sinus. Outer lipflattened from varix to lip’s edge, inrolled at edge from above stromboid notch to anal sinus, and strengthened by an axial fold near the edge of the lip; edge forms a very low arc, almost straight, from the anal sinus to the stromboid notch. Stromboid notch very weak. Anal sinusa deep notch with a rounded apex that adjoins the suture behind the parietal callus. Inner lipthick, detached anteriorly, thin on the parietal wall forming a parietal lobe posteriorly. Anterior canalvery short, open, deeply notched, edge upturned dorsally. Anterior fasciole moderately swollen, with about 6 spiral ridges. Colorcreamy white with 4 light golden brown bands, the widest mid-whorl, and all partially interrupted by white rib crests; aperture white. Bands are pale brown to reddish brown on paratypes.   Remarks. Taxonomy. Splendrillia comptahas most of the characteristics of the genus  Splendrilliain possessing a glossy shell without spiral sculpture, a very short anterior canal with no post stromboid notch inflection of the outer lip, and anal sinus that hooks up to the suture behind the parietal lobe. It diverges from most members of the genus in that it lacks a completely bare sulcus as ribs are present, though much reduced, possessing a varix that is narrow, not hump-like, and in having ribs that extend to the anterior fasciole. The ribs terminate just below the whorl periphery on the base of most members of the genus. The characteristics of  S. comptaare more closely allied to  Splendrilliathan any other genus but the differences suggest the possibility of an as yet unnamed subgroup within the genus. Variability. The four specimens have an average total length of 11.65 mm(10.2–13.0 mm) and an average W/ L ratioof 0.404. The color of the spiral bands varies among individuals. Identification.  Splendrillia comptais closest to  S. masinoi, new species, and it is somewhat similar in color pattern and size to  S. karukeraensis, new species,  S. cruzensis, new species. From  S. masinoiit differs in having longer, more convex but less angular ribs and a narrower varix. The shell appears stockier and color patterning is also different. From  S. karukeraensisand  S. cruzensisit differs in possessing higher, more convex ribs that are only slightly opisthocline, not low and noticeably opisthocline as in the latter two species. These latter two also have a wider, smoother sulcus, and different coloration.   Etymology.The Ornate  Splendrillia. From the Latin adjective comptus, meaning adorned or ornate, feminine  compta, a reference to the pretty effect of spiral bands of color, which vary among specimens, on well-formed glossy ribs.