Johnson.— Polycliaeta 
PLATE 17. 
Figs. 172-174. Lmiice heterobranchia. 
Fig. 172. One of the first, pair of gills ; only one branch is given in detail. X 9. 
Fig. 173. Capillary, double-bordered thoracic seta. X 187. 
Fig. 174. Uncinus from nineteenth (thoracic) somite, x 321. 
Figs. 175-178. Thelepus crispus. 
Fig. 175. Two gill-filaments, showing place of attachment to body. In glycer¬ 
ine. The blood-vessels show through the translucent walls. X 9. 
Figs. 170, 177. Two capillary double-bordered setae of differing form, x 150. 
Fig. 178. Uncinus from thirty-second (thoracic) somite, profile view. X 321. 
Fig. 178 a, b. Two thoracic uncini of slightly different form. X 350. 
Figs. 179-183. Bispira poli/morpha. 
Fig. 179. Anterior portion, ventral aspect, including thorax and first six so¬ 
mites of abdomen. Free-hand drawing. X 2 (circa). 
Fig. 180. Winged seta from dorsal portion of sixth fascicle. X 1-50. 
Fig. 181. Spatulo-mucronate seta-tip from ventral portion of sixth fascicle. X 
275. 
Fig. 182. Avicular and mucronate uncini from sixth torus, in their normal re¬ 
lation to each other. X 150. 
Fig. 183. Avicular uncinus from abdominal region (twentieth toms). X 150. 
