« Its shape is that of the ordinary, or Forskal’s Hyala; but the projection of the upper leaf is much larger and as long as the body, the lateral appendages of which are extremely protruding, very posterior, and as if curved back, which gives the entire shell the shape of an equilateral triangle. The fins of the animal are round and not bilobed. » – H. M. D. de Blainville: “Hyale, Hyalaea (Malacoz.)” in F. Cuvier: Dictionnaire des sciences naturelles vol. 22, Paris 1821, p.81.

« The ventral lip is of moderate size and shows a distinct median depression. The sharp lateral spines are slightly bent, laterally protruding and slightly hooked; the gutter corners are large. The ventral side is globular. The 17 ventral ribs are lineshaped and thin, composed of small tubercles. The lateral lines are a little bit convex and the flanks are slightly developed. The dorsal side is slightly convex, with well-developed central rib, lateral ribs, and lock ribs. » – van der Spoel, Bleeker & Kobayashi: “From Cavolinia longirostris to twenty-four Diacavolinia taxa, with a phylogenetic discussion”, Bijdragen tot de Dierkunde vol. 62(3), Leiden 1993, p.132.

« Morphologically related species are: D. souleyeti, with a much more slender rostrum, D. limbata, a much larger species, and D. deblainvillei that has much more ventral ribs and shorter, more sharply hooked lateral spines. The ventral ribs in this species are always thin but in a few specimens transversal lines on the ribs make these comb-shaped. » – Op. cit. p. 133.