Sculpture ratio, a quantification of shell texture based on a ratio of two measurements, for three Holocene snail species (Mollusca: Gastropoda: Thiaridae: Melanoides), from Bocxlaer and Schultheiß (2010).  
  Part of: Egloff W, Agosti D, Kishor P, Patterson D, Miller J (2017) Copyright and the Use of Images as Biodiversity Data. Research Ideas and Outcomes 3: e12502. https://doi.org/10.3897/rio.3.e12502