Dentitheca Stechow, 1919

Agís, José Ansín, Vervoort, Willem & Ramil, Fran, 2014, Hydroids of the families Kirchenpaueriidae Stechow, 1921 and Plumulariidae McCrady, 1859 (Cnidaria, Hydrozoa) collected in the Western Pacific Ocean by various French Expeditions, Zoosystema 36 (4), pp. 789-840 : 813-814

Genus Dentitheca Stechow, 1919

Dentitheca hertwigi ( Stechow, 1909) ( Fig. 14 ; Table 10)

Plumularia Hertwigi Stechow, 1909: 76 , pl. I, fig. 9, pl. VI, figs 1-3; 1913: 93; 1919: 117, fig. T1.

Dentitheca hertwigi – Hirohito 1995: 261, fig. 88a-e.

MATERIAL EXAMINED. — Type material of Dentitheca hertwigi Stechow, 1909 : ZSM 20041700. Sagami Bay, near Misaki, Japan, depth 15-20 m, Doflein Expedition, 11-X-1904, One slide. ZSM 20051235, Sagami Bay, near Misaki, Japan, depth 15-20 m, Doflein Expedition, X-1904, one slide.

DISTRIBUTION. — Dentitheca hertwigi is known only from Japan waters ( Stechow 1909, Hirohito 1995).

REMARKS

Dentitheca hertwigi , type species of Dentitheca Stechow, 1919 ( Millard, 1975) , is characterized by the morphology of its hydrothecae, with two large triangular lobes on the hydrothecal margin. This is the diagnostic character of the genus according to Stechow (1923b) and Bouillon et al. (2006) (fig.14B, C). Plumularia habereri lacks such triangular lobes, and its hydrothecal margin is straight and only lowered in the adcauline side, not produced. Plumularia asymmetrica Bale, 1914 was included in the synonymy of P. hertwigi by Schuchert (2014b), but the asymmetrical morphology of the hydrothecal margin, with only one lateral lobe, and the presence of an intrathecal septum in the abcauline wall of the hydrotheca clearly separates both species. The presence of the intrathecal septum approaches that in P. elongata , but it is distinguished by the single marginal lobe ( Bale 1914; pl. IV, figs 2-3).

Genus Plumularia Lamarck, 1816

Figures

FIG. 14.— Dentitheca hertwigi (Stechow,1909),type material,ZSM 20041700:A, first internodes of hydrocladia,lateral view;B, internodes from half of hydrocladia, lateral view; C, distal internodes of hydrocladia, lateral view; D, internode, frontal view. Scale bars: 0.1 mm.