16 IOWA STUDIES IN NATURAL HISTORY 
ARABELLA Grube 
Arabella setosa Verrill 
Arabella setosa Verrill, (1900), pp. 651 to 653. 
One specimen collected at Pillars of Hercules and two at 
Station 99. 
OENONE Savigny 
Ocnone diphyllidia Schmarda 
Oenone diphyllidia Schmarda, (1861), p. 120, pl. XXXII, fig. 256. 
One incomplete specimen at Station 90 and one from ‘‘old 
coral heads.’’ 
Family Cirratulide 
CrrraATuLUS Lamarck 
Cirratulus nigromaculata Treadwell 
Cirratulus nigromaculata Treadwell, (1901), p. 204, fig. 66. 
One specimen, collected at Pillars of Hercules. 
Cirratulus melanacanthus Grube 
Cirratulus melanacanthus Grube. Quoted from Ehlers, (1887), pp. 155, 156. 
One specimen marked as collected ‘‘off Lord’s Castle—Sta- 
tion 25256.’’ 
Family Maldanide 
NicomacHE Malmgren 
Nicomache antiguensis new species 
Fragments of two specimens were in one bottle labeled as 
collected at Pillars of Hercules. One fragment retained the 
prostomium and fourteen somites, the other the prostomium and 
five somites. An anal somite with eight attached somites was 
also in the bottle. It is impossible to tell to which of the two 
anterior fragments the anal somite belonged, but a comparison 
of the somites shows that they belong to the same species. A 
fragment of another specimen was collected at Pelican Island. 
A lateral view of the prostomium (figure 25) shows a prominent an- 
terior margin overhanging the mouth and extending to the sides of it 
but not continued posteriorly. The dorsal crest of the prostomium is 
rounded and extends through about a quarter of a circle. The nuchal 
organ is visible from the side as a depression near the antero-lateral sur- 
face of the prostomium. On a dorsal view the nuchal organs appear on 
either side as inverted V’s with equal arms about one-third as long as 
the prostomium. 
In preserved material the width of somite 1 is nearly twice its length; 
somites 2, 3 and 4 are equal to one another each being about one-third 
longer than somite 1. Somite 5 is three times as long as somite 4. In 
