|Revised Benson (1966, 1983) taxonomy|
Richard N. Benson (10/06/2004)
|Benson (1966, p. 523-527) included two forms in his description of Siphocampium cf. cornutella Haeckel from the Gulf of California. Most tests conform to Jørgensen’s (1905, p. 140) description of Stichocorys seriata:|
“A many-jointed form. The uppermost joints are convex and increase in size so that the diameter of the fifth is from three to four times as great as that of the first. The lower part is more or less distinctly cylindrical. On the cephalis, there is a short broad tophorn. The pores below are roundish rectangular, in very distinct, regular, horizontal rows.”
Although similar to Spirocyrtis gyroscalaris Nigrini, the tests from the Gulf with rounded abdominal joints terminate with a narrower cylindrical joint, although Benson (1983, p. 508) included those forms (Benson, 1966, pl. 35, figs. 14-15) in Spirocyrtis gyroscalaris. Nigrini (1977, p. 258-259) does not describe nor illustrate tests conforming to this species with a terminal cylindrical joint.
The other, less abundant form from the Gulf, conforms to Spirocyrtis scalaris Haeckel as described and illustrated by Nigrini (1967, 1977). Although Benson (1983) included the form illustrated in figure 15 of his 1966 plate 35 within Spirocyrtis gyroscalaris, it tends toward angular abdominal shoulders; therefore, I now assign it to Spirocyrtis scalaris.