LEODICID.E OF THE WEST INDIAN REGION. 



109 



plate of the form shown in text-figure 404, but with very indefinite outlines. This I 

 consider similar to the plate shown in text-figure 398, and not homologous with the 

 mandibles of other genera. I was unable to find any true mandibles. 



There is but one form of seta (text-figure 405). This is rather small, much curved 

 toward the apex, and with a narrow wing along the convex margin. Each parapodium 

 has a strong acicula extending to some distance beyond the setal lobe. Each acicula 

 has a narrow lanceolate apex with a shallow longitudinal groove on its surface (text- 

 figure 406). 



One specimen had 338 somites and was 365 mm. long. Apparently the posterior 

 end was entire, but I could find no trace of anal cirri or lobes. 



Type in the American Museum of Natural History. 



Drilonereis longa Webster. 



TEXT-FIGURES 407 to 411. 



Drilonereis longa Webster, 1879, p. 40, plate vn, figures 84-88. 



Laranda longa Mclntosh, 1885, p. 237, plate xxx, figure 10; plate xxxvn, figure 5; text-figure 3. 



A very slender species, looking very like D. attenuata and very similar to it in size. 

 The body is less than a millimeter in width, and there are several hundred somites. 

 Only the anterior portions of two specimens were collected at Mangrove Key in Key 

 West Harbor in July 1915. 



The prostomium (text-figures 407 and 408) is more pointed than D. attenuata, and 

 there arc no eyes. The boundary between the prostomium and the peristomium is 

 very indistinct on the dorsal surface, but more marked laterally. In the median 

 dorsal line is a longitudinal groove, extending over the prostomium and the first somite. 

 Later somites are a little wider than the first, but not quite so long. I did not find the 

 posterior end. 



The parapodia are practically absent in the 

 anterior somites, being represented by a very 

 slight elevation carrying setae. Later they be- 

 come more prominent, and through the middle 

 of the body have a relatively rather heavy 

 posterior-ventral lobe (text-figure 409). Web- 

 ster (loc. cit., p. 40, and plate vn, figure 86) 

 describes a second lobe, which appears only in 

 posterior somites. This did not appear in any 

 of my material and probably the specimen did 

 not retain enough of the posterior regions to 

 show this structure. The parapodium contains 

 a pair of heavy aciculae and simple setae of two 

 kinds. One (text-figure 410) is expanded and 

 bent toward the apex, tapering to a sharp point 

 and with a wing along the convex margin. 

 Beyond the wing the margin is provided with 

 a row of very small but clearly marked teeth. 

 The second form of simple seise are very slender 

 and needle-like. 



The maxilla (text-figure 411) has a long, 

 slender carrier with rather stout forceps, much 

 curved at the ends, and with teeth along the 

 inner edge of the basal portion of each half. 



411 



TEXT-FIGURES 407 to 411. 

 Drilonereis longa Webster. 



407. Lateral view of head x!8. 



408. Dorsal view of head x!8. 



409. Parapodium x200. 



410. Seta x666. 



411. Jaw apparatus x26. 



