Lissotrochus Cairns 2004, n.gen.

Lissotrochus n.gen.

Diagnosis. Corallum ceratoid and cornute, with a pointed base. Calice elliptical in cross section; GCD up to 3.25 mm. Costae broad and rounded, bearing tiny spines laterally; intercostal regions deep and narrow, not pitted or porous; most of theca covered by a thin epitheca. Higher cycle costae originate by trifurcation; costae correspond to septa; C: S = 1. Septa exsert and hexamerally arranged in 4 incomplete cycles. Paliform lobes present before S2 and sometimes P3. Columella papillose.

Type species. Lissotrochus curvatus, here designated.

Remarks. Among the 28 turbinoliid genera (Cairns, 1997), Lissotrochus is most similar to Cryptotrochus and Pleotrochus, all three genera having an imperforate theca without transverse division, P2, a papillose columella, and four cycles of septa. But, Lissotrochus is quite different from both genera in its cornute, ceratoid shape; smooth (not serrate) costae; elliptical (not round) calice; presence of both P2 and P3 as paliform lobes; and in having an extensive epithecal covering. It is further distinguished from Pleotrochus by having costal trifurcations and the same number of costae as septa, and from Cryptotrochus by having independently arranged septa.

Etymology. lissos, Greek for “smooth” + trochos, Greek for “wheel”, the latter a common suffix of coral generic names., an allusion to the smooth epitheca of this genus. Gender: masculine.