LEODICID^ OF THE WEST INDIAN REGION. 51 



teeth. In the anterior somites there is a single acicula in each parapodium (text-figures 

 144 and 145), but posteriorly (text-figure 146) a second (ventral) one appears. In the 

 anterior region the acicute are colorless, but posteriorly they become, except for the tip, 

 more or less dark brown in color. The dorsal acicula (text-figure 150) has a blunt apex, 

 while the ventral one is curved and bifid (text-figure 151). I could find no trace of 

 needle aciculse in the dorsal cirrus. 



The maxilla (text-figure 152) is light brown in color, with more or less darker mar- 

 gins. The carrier is slender with narrow wings; the forceps is rather straight with dark 

 bands along the inner edge of each basal part, on the concave face of the shaft and where 

 the forceps joins the carrier. The proximal paired plates have 5 teeth on the right and 

 4 on the left; the distal paired plates have 6 on the right and 4 on the left; the unpaired 

 plate has 7. The plates are light in color, but the toothed margins are dark. Crescent- 

 shaped pigment patches occur distal to the plate. The mandible (text-figure 153) has 

 very slender, widely separated shafts marked with longitudinal dark lines and with 

 fine dark lines making concentric curves on the beveled portion. 



L. culebra lives in crevices in the coral rock in close association with Nicidion kin- 

 bergii, which it closely resembles in form and appearance. Most of my specimens were 

 collected at Marshall Island, Bermuda, in 1916, but a single one was dredged in the 

 Northwest Channel at the Dry Tortugas in 1914, and I collected the species in Tobago 

 in 1918. One specimen was taken at Ensenada Honda, Culebra, Porto Rico. 



Leodice tenuis, new species. 



(Plate 4, figure 11; text-figures 154 to 163.) 



Only three specimens of this species were collected in the Tortugas, in 1909, 1913, 

 and 1914, respectively. The first lacked only the anal cirri, the second was complete, 

 and the last retained only the first 372 somites; of this last, a color drawing of the living 

 animal was made (plate 4, figure 11). This specimen was found in loose rock near 

 Loggerhead Key. The 1913 specimen was in a crevice in the coral rock inside a tube of 

 white parchment-like material, evidently of its own manufacture. This was branched, 

 with lateral branches ending blindly. The anterior end of the body is a light yellowish- 

 red, owing much of its color to contained blood. Toward the middle the body is darker 

 colored, on account of the color of the intestinal wall, but there is no surface pigment in 

 any portion of the body. The 1913 specimen, which was entire, was 460 mm. long 

 after preservation and was composed of over 500 somites. All color is lost in preserved 

 material. 



The prostomium is noticeably bilobed (plate 4, figure 11), shorter than the rather 

 slender tentacles. Of these, the median is the longest, with successive diminution in 

 length on the part of the inner and outer paired ones. The nuchal cirri are very slender 

 and white, shorter than somite 1. The dorsal cirri are relatively rather prominent 

 throughout the body. There are two pairs of anal cirri, both rather stout, one pair 

 much longer than the other. The eyes are small but distinct. 



The peristomium is as long as the three following somites, nearly rectangular in out- 

 line. The second somite is short; the following somites (in preserved material) about 

 0.5 mm. in length, while through the middle and posterior regions these reach a length 

 of 1 mm. 



The first parapodium (text-figure 154) has very prominent dorsal and ventral cirri; 

 the post-setal lobe is longer than the anterior and a dark acicula extends into it; a tuft of 

 needle aciculse extends into the dorsal cirrus. The tenth parapodium (text-figure 155) 

 has a relatively more slender but still prominent dorsal cirrus, while the ventral cirrus 

 has decreased to a short lobe at the end of a prominent pad. The setal portion is about 



