82 LEODICID^E OF THE WEST INDIAN REGION. 



Genus NEMATONEREIS Schmarda. 



L. K. Schmarda, Neue Wirbellose Thiere, etc., 1861, p. 119. 



Prostomium rounded, with one tentacle. Parapodium with dorsal and ventral 

 cirri, simple and compound setae. The maxilla has an unequal number of plates on the 

 two sides. 



Ehlers (1864-1868, p. 373) regarded Nematonereis as a connecting link between 

 Lumbrinereis and Lysidice, basing this opinion on the reduced number of tentacles and 

 the jaw apparatus. 



Nematonereis hebes Verrill. 



(Text-figures 288 to 297.) 

 Nematonereis hebes Verrill, 1900, p. 647. 



A small species, specimens in my collection from Marshall Island, Bermuda, meas- 

 uring about 12 mm. in length, with a prostomial width of not over 0.25 mm. and the 

 greatest body-width, at a very short distance behind the head, of about 0.5 mm. There 

 were about 75 somites. Verrill's specimens from Bermuda were 0.3 mm. in width, but 

 25 to 30 mm. long. I have studied two individuals from my own collection and one 

 from Verrill's. No drawings were made of the living animal. 



The prostomium (text-figures 288 and 289) is broadly rounded in front and a little 

 broader than long. There is one median tentacle which is constricted at the base and 

 swollen just beyond this. It terminates in an acute tip just behind the anterior border 

 of the prostomium. There is one pair of small black eyes. The peristomium in preserved 

 material is rather shorter than the prostomium and a little longer than somite 2. The 

 parapodia begin on somite 3. The first parapodium (text-figure 290) has a rather 

 large postero-ventral lobe, which is joined to the ventral cirrus, and a finger-shaped 

 dorsal cirrus. There are a few setse (2 simple and 2 compound in the one drawn) and 

 a single acicula which reaches only to the surface. This is colorless, except for a short 

 space about one-third of its length from the base, where it has a brownish center. The 

 immediately following parapodia are very similar to this, but the setal lobe becomes 

 broader and the post-setal lobe more rounded. The tenth parapodium (text-figure 291) 

 has a conical ventral cirrus closely adherent to the setal portion; dorsal cirrus long and 

 slender, as long as the parapodium. The posterior lip is rounded and the anterior one 

 vertical. There is a straight acicula which is mostly colorless, but has a central brown 

 axis for a part of its length; dorsal to this is another straight, colorless acicula, similar 

 but shorter. As far back as about the fourteenth setigerous somite the parapodia are 

 prominent and the somites are wider than long. Posterior to this point the somites 

 elongate and the parapodia become relatively less prominent. They are more pointed 

 at the apex, the larger dorsal acicula protruding from the apex. A ventral acicula 

 (text-figure 292) with a bidentate hooded apex occurs. 



Setae are of three kinds. The simple is very slender (text-figure 293), enlarged 

 toward the apex, and drawn out into a fine point. The one figured was taken from the 

 first somite. Some of these simple setse are bent very decidedly at the enlarged portion, 

 but otherwise are similar to the one drawn. The compound seta (text-figure 294) 

 has a relatively very long shaft, enlarged and finely denticulated at the apex, the ter- 

 minal joint being short, bidentate at the apex, and with a small hood. The pectinate 

 setse possibly vary in different parts of the body, being perhaps larger posteriorly than 

 anteriorly. I was unable to demonstrate them on all somites and can not be certain 

 on this point. The one figured (text-figure 295) was taken from a posterior somite 

 and was very broad in comparison with the tuft of other setae, so that the shafts of the 

 latter seemed to lie in the concavity of the pectinate. 



