Stromboidea

• Aporrhaidae
  • Dimorphosoma
    • Dimorphosoma neglecta (Tate, 1865)

Original Description of Aporrhais (Perissoptera) neglecta by Tate, 1865, page 102 :

• "Shell elongated, composed of slighly angular whorls; upper whorls whith a strong median keel, and a faint one immediately above the anterior suture; ornemented transversely by numerous, oblique, flexuous, equidistant ribs; the ribs are imperfectly defined upon the upper half of the whorls; the whorls are further ornamented by longitudinal striae. The last whorl strongly striated, without transverse ribs; bicarinated, the posterior carina the larger, and continued into the wing; lip prolonged into a very free wing, narrow and carinated above, curved at the base; terminating posteriorly in a long, moderately sharply curved point; mouth narrow, callosity on the columella excessive; canal short."

Dimensions: Lenght, without canal, 12mm; breadth, including wing, 13mm. ; breadth of last whorl, 5mm.

Affinities and differences: It is closely allied to A. calcarata, with which it has been long confounded; it differs in its superior size; more obtuse, spiral angle, in its carinated whorls, more gibbous, body whorl; greater lenght of wing, and in the less abrupting curvature of the free point. In Aporrhais calcarata, the flexuous ribs are very distinct, but in Aporrhais neglecta, they are barely conspicuous (and are more numerous) even upon the lower half of the whorl.

Stratum typicum: Greensand of Blackdown, Albian, lower Cretaceous

Locus typicus: Greensand, Blackdown, Devon, England

History and Synonymy

1875

Dimorphosoma neglecta in Gardner, 1875, pl. XII, figs. 13, 13a, 14, 15

1996

Woods & Jones, 1996 reported Drepanocheilus neglecta from Horizon B of the Upper Albian, Mortoniceras (M.) inflatum zone, H. varicosum subzone

References

• Woods, M. A. and Jones, N. S. 1996. The sedimentology and biostratigraphy of a temporary exposure of Blackdown Greensand (Lower Cretaceous, Upper Albian) at Blackborough, Devon. Proceedings of the Ussher Society, 9, 037-040.