LOPADORRHYNCHUS PARVUM. 115 



have each a distinct, short ceratophore and a stout conical style reaching to the 

 second metastomial somite. At the base on the ventral side is a minute ventral 

 cirrus. The posterior cirrus in form and size agrees with the anterior dorsal. 



The metastomial somites, as usual, are very flat ventrally and moderately 

 arched dorsally, the body as a whole appearing flattened. The first one has its 

 ends ventrally bent forward about the labial area, so that it appears to be ex- 

 cavated anteriorly. The next somite is also slightly bowed in a similar way, 

 while the next two are c^oncave on the anterior side but straight behind. Dor- 

 sally all the somites are double, being crossed by a distinct transverse furrow. 

 In the anterior region this furrow divides the somites nearly equally, but in the 

 caudal region it lies much nearer to the caudal border. The somites increase 

 in actual length to near the middle of the body. Behind the middle,, while 

 decreasing in width, they maintain nearly the same actual length until near the 

 caudal end. The pygidium is narrow, rather longer than wide, a little narrowed 

 at the caudal end, and with the caudal margin a little indented. The anal 

 cirri in the types are lost. 



The first three pairs of parapodia are short and stout, increasing in size 

 from the first to the third. They are very deep dorsoventrally, and when viewed 

 from in front or behind, are seen to be widely convexly rounded. In ventral 

 view they narrow to an acute edge distally. There is a small presetal lobe, and 

 caudad of the setae a low, broadly rounded, postsetal lobe continued a short 

 distance down the ventral side. In these first three parapodia there is no trace 

 of true neurocirri, though at the base of each there is a swelling hke that to which 

 the styles of normal parapodia are attached. The notocirri of these anterior 

 parapodia have cirrophores that are short, thick, and distinct. The styles are 

 also very thick and conical in form, not extending distad noticeably beyond the 

 end of the neuropodium proper. Caudad of the third pair the parapodia become 

 longer and more strongly flattened in the anterocaudal direction. The post- 

 setal lobe becomes somewhat higher and at its distal end a little more pointed. 

 In addition there is a conspicuous presetal lobe which extends wholly across the 

 end of the neuropodium and becomes high. On all, the notocirri continue to 

 be present and of essentially the same conical form as those of the first parapodia. 

 Neurocirri are also present, these being likewise of a stout, conical form, but 

 somewhat smaller than the corresponding notocirri. (Plate 17, fig. 6). 



The first three pau's of parapodia bear only simple setae. These are of 

 the usual type, transparent, stout, distally acute, and with the tips curved caudad. 

 In the type the normal number in each neuropodium is six, of which the most 



