&86 pN THE POLYCn.i:TA OF THE MALDIVE ARCHIPELAGO. [Feb. 16, 



EXPLANATION OF THE PLATES. 

 For lettering, see helow. 



Plate XVI II. 



Fig. 1. Chcetopterus loncfimanus (p. 272). Two of the thickened and flattened sets 

 of the 4th foot, showing the extreme forms met with in the same bundle. 

 X70. 



2. Uncini (a) from inner half of neuropodial torus of C ; (b) from outer half of 



the same ; (c) fi-om the neuropodial torus of last foot of A. All X 350. 



3. Thylloclicetopterus acimligerus (p. 278). Dorsal view of head and fore part 



oip bodj^ The long tentacles are lost. X 10. 



4. The point of one of the acicula from the 4th foot. X 70. 



5. Setffi of the region A : — a & h from the 5th foot ; c & cl from the last. X 70. 



a is the normal form in the 5th foot, but dorsally are a few like h. In the 

 last foot most are like c, others like d, and a few like a. 



6. The mid-body (region B) together with adjoining segments of A & C. X 10. 



7. An uncinus from the ventral division of the fifth neuropodium of C. X 350. 



Plate XIX. 



Fig. 1. Chcetopterus longipes (p. 277). Uncini from various feet -.—a & h two 

 uncini situated near together on the first neuropodial torus of B ; c from 

 an outer and d from an inner torus of C. X 350. 



2. Strong set* from the 4th foot of A. X 70. 



3. Fhi/lloclicetopterus gardineri (p. 280). Dorsal view of head and anterior 



segments. The specimen is a little contracted. X 10. 



4. Various setae : — a, from the 4th foot of A ; 6, a bent seta from the same ; 



c, from the last foot of A ; d, an uncinus from the first neuropodium of B. 

 a, h,&c, X 70; d,X 350. 



5. Drawing of an excised segment of the region B, as seen from in front, 



showing parapodial gills, black gut, epithelium, &c. X 10. 



6. Ventral view of three segments of mid-bodj^, showing relative positions and 



sizes of the parts of the neuropodia. X 10. 



7. One of the clavate notopodia of the region C as seen in optical longitudinal 



section. X 70. 



8. Si/alincecia camiguina (p. 281). Upper jaw -plates. The darker shading 



represents brown chitin, the lighter calcareous matter. X 60. 



9. One of the lower jaw-plates of a larger specimen. X 60. 



10.' Group of four kinds of setae, from a parapodium near the hind end of the 



v^orm. (The combs are often much more numerous.) 

 11. Group of special setae in situ from the 2nd foot. X 320. 



^Explanation of the lettering. 



ec8.=ccelom. 

 <^.c77.=dorsal ciliated groove. 



.(7. = gut. 

 _(^,7?. = triangular membranous flap between the noto- and neuropodia. 

 ^7. = glandular apparatus adjoining the gills. 

 ?H.=muscle. 



neur.d.= f (jo^.g^l and ventral parts of the neuropodia. 

 neur.v.^ ) 



«oi.=notopodium. 

 _peri.=peristomial collar. 

 ipxo.^= prostom ium . 

 ^j?(/;.4= fourth parapodium. 

 s. = seta. 

 i.^= second pair of tentacles. 



