LEODICID^ OF THE WEST INDIAN REGION. 47 



Museum has a specimen from Nassau. I did not find it in Bermuda and there is no 

 record of its occurrence there. I found a few in Tobago in 1918 and it was common in 

 Montego Bay, Jamaica, in 1921. The U. S. National Museum has specimens from Cape 

 Florida and from latitude N. 9° 32', longitude W. 79° 54' 30", in 34 fathoms. 



Leodice cariboea Grube. 



(Plate 4, figures 1 to 4; text-figures 136 to 143.) 



Eunice caribcea Grube, 1856, p. 57. 

 Eunice siciliensis Treadwell, 1901, p. 196. 



A species recognizable by the relatively enormous development of the mandibles 

 as compared with the maxillae (compare text-figures 136 and 137) and by the very feeble 

 development of gills. 



The body of an adult is long, some that I collected containing over 700 somites. 

 The anterior region of the body, as far back as approximately the fiftieth somite, is 

 usually more or less flattened dorso-ventrally, being plane or even concave on the ven- 

 tral surface; but behind this region it becomes rounder and more narrow. In removing 

 animals from the coral rocks, one often finds this anterior flattened portion bent sharply 

 on itself and wedged tightly in a rock crevice. The prostomium is large and usually 

 bent ventrally, so as to form an angle of about 45° with the peristomium. It is a faint 

 greenish yellow in color, and this is continued onto the surface of the peristomium. The 

 yellow tint of the body is continued to about somite SO, and some 50 following somites 

 are dark gray, due probably to the chlorogogue layer of the intestine. Behind this region 

 the body is transparent in immature animals, but in sexually mature ones is colored 

 by the sex products. In one specimen of 340 somites the transition to the chlorogogue 

 region occurred between somite 90 and 100, and this gray region extended to somite 

 168. The first eggs appeared at somite 191, and these filled the body to about somite 

 270. Throughout this sexual region there is a prominent black spot in the midventral 

 line in each somite, and some somites show a black spot at the base of each parapodium. 

 Occasionally there will appear an individual in which this sexual region is as sharply 

 defined as it is in L. fucata (see p. 43), and the animal looks as if it might swarm on the 

 approach of sexual maturity. A similar condition was described by Moore (1909, p. 

 246), in a Pacific Leodice to which he gave the name paloloides because of this structural 

 resemblance to a swarming palolo (see p. 43). A comparison of cariboea with paloloides 

 shows that the two are distinct though closely related species, and it is possible that they 

 really swarm, though no evidence in confirmation of this belief has yet been found. 



The tentacles (plate 4, figure 2) are rather longer than in Grube's description, the 

 inner laterals a little longer than the outer and a little shorter than the median. The 

 peristomium (plate 4, figure 2) is as long as the three following somites, its width being 

 nearly twice its length. The following somites are very convex dorsally and are broad 

 in proportion to their length. To a certain extent this appearance is due to the stimulus 

 of being handled. Median and posterior somites are nearly round in cross-section and 

 much longer in proportion to their width. The anterior dorsal cirri (text-figure 138) 

 are large, but toward the posterior end they become very small (text-figure 139). There 

 are two pairs of small anal cirri of unequal size (plate 4, figure 4). 



The gills are very inconspicuous, appearing as a single filament first in the region 

 of somites 80 to 90 and occur for about 110 somites. In the living animals, when the 

 gills are filled with blood they are easy to see, but in preserved material they are hard to 

 find, and small members of the species are apt to be taken for Nicidion. Usually there 

 is but one filament (text-figure 139), but occasionally there may be a second, and I 

 found one individual in which a trifid gill appeared on somite 105. 



