1907.] NATURAL .SCIENCES OF PHILADELPHIA. 205 



eyes. Tentacular cirri missing, their faint scars of attachment on the 

 dorsum of the lateral lobes just anterior to the level of the eyes. Body 

 segments short and rather indistinctly defined ; much concealed by the 

 foliaceous parts of the parapodia; body rather strongly depressed, 

 gently convex above and below. 



Parapodia very conspicuous, so large that they completely envelop 

 the body and give somewhat the appearance of a series of thin disks 

 strong upon an excentric band. They are very broadly attached and 

 the two rami nearly continuous, with extended setigerous tubercles, 

 low presetal lobes, and very large and foliaceous postsetal lamellae. 

 The first (fig. 31) is relatively small and lies by the side of the prosto- 

 mium, the posterior part of which is crossed by the notopodial setae. 

 On the next few both postsetal lamellse increase rapidly in size, the 

 notopodial soon predominating over the neuropodial and extending 

 dorsalty and ventrally. In this region the neuropodial lamella (fig. 

 32) is formed much like the quadrant of a circular disk, and the noto- 

 podial lamella like a narrow palette, broadly rounded above and with 

 an auricular process below which is absent or little developed in the 

 most anterior parapodia. The notopodial lamellae meet or overlap 

 medially and touch the neuropodial lamella below. After somite XXX 

 the notopodium gradually becomes smaller and withdraws from the 

 dorsum. By XXX^TII it is strictly lateral and its postsetal lamellae 

 is no larger than that of the neuropodium, and leaves the dorsum 

 entirely exposed. Simultaneously with this change a delicate trans- 

 verse integumental fold appears on the dorsum, connecting the bases 

 of the notopodial lamelke of the two sides. At first quite insignificant, 

 these increase in height as the branchiae diminish and by XLII their 

 lateral parts are nearly half as high as the lamellae which they connect, 

 but the medial part is much lower. 



The first 3 pairs of ])arapodia are free, but all others are united con- 

 tinuously along each side by a thin lateral fold of integument, which is 

 attached to the sides of the body ventrally and whose dorsal border is 

 free between the parapodia but attached to each neuropodium for the 

 full height of its base and for a short distance above it. Thus is formed 

 a series of deep interpodal pockets widely open above. 



Branchiae arise from the dorsum just above the base of the notopodial 

 lamella from III to XLII inclusive, largely concealed behind the 

 medial ends of the lamellae. The first 2 or 3 are rather small, but they 

 soon increase in size and rise erect far above the notopodial lamellae. 

 The last 10 gradually diminish before they finally disappear. Typical 

 branchiae (fig. 32) are more or less flattened, ligulate, tapered and 



