LEODICID^ OF THE WEST INDIAN REGION. 57 



Genus MARPHYSA Savigny. 



J. C. Savigny, SystSme des Ann^lides, 1S20, p. 13. 



Prostomium lobed, with five tentacles and with or without eyes. No nuchal cirri. 

 Parapodia begin on the third body somite and gills occur attached to the dorsal cirri of 

 a greater or lesser number of parapodia. The jaw apparatus, like that of Leodice, is com- 

 posed of a maxilla and a mandible, the former of forceps plates supported on a carrier, 

 together with two sets of paired and one unpaired plate and smaller accessory plates. 

 The mandible is of two parts, united anteriorly and has a beveled cutting-edge. The 

 terminal joint of the compound seta is often long and acute with entire edges. 



Grube (1851, p. 44) lists these simply as Eunice without tentacular cirri, and this 

 usage is followed in his later work (1856, p. 60), though he gives Savigny 's division 

 "Leodicse Marphysse" in parenthesis; Schmarda (1861) did not differentiate between 

 Eunice and Marphysa; Quatrefages (1865a, p. 331) was the first to separate the two 

 as distinct genera. Kinberg (1864, p. 561) divided Marphysa into Nauphanta and 

 Nausicaa, depending on the form of the gills, but neither genus is now recognized. 



Marphysa acicularum Webster. 



(Plate 5, figures 1 to 4; text-figures 184 to 193.) 



Marphysa acieidarum Webster, 1884, p. 319, plate 10, figures 50-53. 

 Marphysa parishii Ehlers, 1887, p. 97. 



A rather large species, over 200 mm. in length and with more than 300 somites. 



A Tortugas specimen has the prostomium a yellowish brown except at the base of the 

 tentacles, where there is a colorless patch. The ceratophores are colored like the head, 

 but the terminal portions of the tentacles are much lighter, becoming colorless at the 

 apices (plate 5, figure 2). This dorsal coloration at the head gradually shades at the 

 sides into a colorless lower surface. The peristomium is dark-brown with numerous 

 yellowish spots on the surface, and very iridescent. This dark color is continued onto 

 the following regions, the first six somites being noticeably the darkest portions of the 

 body. Behind the sixth somite the color gradually fades until at about the point of 

 maximum width it passes into a yellowish-gray, which is continued throughout the 

 body. On each somite, immediately following the head, there are yellowish-brown 

 spots, showing a tendency to arrange themselves in median transverse bands. On the 

 ventral surface a faint brownish coloration extends back to about the thirtieth somite and 

 behind this the ventral surface is colored like the dorsal. Specimens collected in Ber- 

 muda had much less pigmentation than is described above, the body tint being almost 

 entirely due to the blood in the vessels of the body wall and to the gills, though there 

 was always a good deal of iridescence. The posterior region is usually very transparent, 

 so that the intestinal contents can be seen through the body-wall. 



The prostomium (plate 5, figures 1 and 2) is noticeably bilobed as seen from above, 

 but four-lobed when viewed from below. The peristomium is nearly rectangular in 

 outline, narrower than the prostomium and three times as long as the second somite. 

 The following somites are about equal in length to the second, but there is a gradual 

 increase in width up to a maximum between somites 30 and 40, with a gradual 

 decrease toward the posterior end. 



The tentacles (plate 5, figures 1 and 2) are about twice as long as the prostomium 

 and show the usual gradation in length from the median outward. The dorsal cirri are 

 never very large and throughout most of the body are rather small. There is one pair 

 of long and a second much shorter pair of anal cirri (plate 5, figure 4). 



Webster stated that the gills begin on somites 25 to 29. One Tortugas specimen 

 showed them beginning on somite 25 with a single filament, while in another they began 



