114 • • THE ANNELIDA POLYCHAETA. 



the Atlantic Ocean and the Mediterranean Sea. Two apparently new species 

 occur in the present collection. They may be distinguished from the other 

 species and from each other by means of the following key. 



Key to Species. 



a. Neurocirri absent or much reduced and transformed on the first three setigerous somites. 

 6. Exclusively simple setae on only the first two pairs of neuropodia. . . .L. krohnii (Claparede). 

 hb. Exclusively simple setae on the first three pairs of neuropodia. 



c. The fourth neuropodia bear exclusively simple setae in the ventral half, the following neuro- 

 podia bearing but one or two simple setae L. nans, sp. nov. 



cc. The fourth like the following neuropodia in having but one or two simple setae. 



d. Eyes present, distinct; cirri slender L. breve Grube. 



dd. No eyes; cirri proximally very stout L. parvum, sp. nov. 



aa. Neurocirri absent or reduced on only the first two setigerous somites. The number of simple 

 setae on the neuropodia decreases gradually in going eaudad L. viguieri Reibisch. 



LOPADORRHYNCHUS PARVUM, Sp. nOV.^ 



Plate 17, fig. 6, 7. 



The color at present is grey of a brownish cast, the parapodia, cirri, and 

 tentacles palest. 



The two type-specimens are very small. The larger one is 4.8 mm. long 

 and consists of nineteen somites. The other specimen is 4 mm. long and also 

 is composed of nineteen somites. The body in outline as seen from above is 

 widest in front of the middle, strongly narrowed and pointed eaudad, and also 

 narrowed and rounded cephalad. 



The prostomium is broad, with the anterior margin mesally incurved, and 

 the tentacles attached far apart at the anterior corners and somewhat beneath. 

 The prostomium is depressed below the level of the peristomial region and is 

 thin dorsoventrally. On each side the dorsal tentacle is much stouter and longer 

 than the ventral one and extends ectad. The ventral one, which is contiguous 

 with the dorsal one at base, projects ventrad and nearly at right angles to the 

 axis of the dorsal one. 



Ventrally the peristomium presents a subquadrangular area, or Up, wider 

 than long, the caudal border of which projects into a corresponding excavation 

 in the second somite. Dorsally it is apparently fused with the prostomimn, 

 but is distinguished by being distinctly more elevated as a thick transverse 

 ridge. There are three pairs of tentacular cirri. Of these the anterior dorsals 



' parvus, small. 



