1904. 

 1909. 

 1910. 



206 POLYDORA FLAVA. 



1893. Polydora caeca (pro parte), Mesnil. Compt. Rend. Acad. Sc, t. cxvii, p. 643, 1893. 



1894. „ pusilla, Be St. Joseph. Ann. Sc. nat. 7 e ser., xvii, p. 65, pi. iii, figs. 74—77. 



1896. „ flava, Mesnil. Ball. sc. Fr. Belg., t. xxix, p. 182, pi. xi, figs. 18—26, and pi xii fip* s 



1—22. 



„ „ Allen. Journ. M. B. A., n.s., vol. vii, p. 227. 



„ „ Mcintosh. Ann. Nat. Hist., ser. 8, vol. iii, p. 169. 



„ „ Elwes. Journ. M. B. A., vol. ix, p. 62. 



» » „ Southern. Proc. Royal Irish Acad., vol. xxviii, p. 236. 



1914. „ „ Idem. Ibid., vol. xxxi, No. 47, p. 104. 



Habitat. — In chinks of the Bast Rocks, St. Andrews, along with Pygospio. Abundant 

 in its tunnels in Lithothamnion, which coats the hard surface of the gneiss between tide- 

 marks m the Channel Islands in company with Dodecoceria concharum and Potamilla 

 reniformis. "Where no perforations could be made, as at Cobo Bay, Guernsey, it is found 

 m the muddy seams of the hard granite. Large examples in Lithothamnion dredged in 

 Bressay Sound. Between tide-marks, Lochmaddy, North Uist, also boring in Litho- 

 thamnion. The examples were not large. In the Atlantic off Paible, North Uist. Howth, 

 Blacksod and Clew Bays (Southern). Plymouth (Allen). Torquay (Elwes). 



Elsewhere it frequents the shores of France, both Channel and Mediterranean 

 (De St. Joseph, Mesnil). Naples (Claparede). 



Head (Plate XCIII, fig. 3) somewhat resembling that of P. ciliata, but the bifid 

 prostomium is longer and more tapered, and its processes are more distinct, whilst the 

 peristomial support at each side is more evenly rounded, anteriorly and laterally. The 

 divergent processes of the prostomium at once attract attention. A little pigment in 

 some occurs on each side of the median ridge (the prostomium) in front, but distinct eyes 

 have not been seen in life or in the preparations. The median ridge passes backward to 

 the fourth bristled segment. The tentacles extend to the fifteenth segment or beyond. 



Body of considerable proportional size, a little tapered anteriorly and more distinctly 

 posteriorly, where it terminates in a funnel with a more or less even rim, less expanded 

 at the edge than in Polydora ciliata. Attached by the narrow end to the funnel of one 

 example is a pear-shaped crustacean parasite. An unusually long funnel occurred in an 

 example procured at St. Peter Port, Guernsey, in July, but as only a few adjoining 

 segments were attached to it some doubts may exist as to the interpretation of the species. 

 One example, kindly sent by Dr. Allen from Plymouth, had the dorsal margin slightly 

 crenate. As a rule, the ventral margin is more prominent in lateral view. Mesnil found 

 it 4J cm. long and with two hundred and fifteen segments, but generally the specimens 

 are shorter. Those from Cobo Bay, Guernsey, were 2 inches in length, and those from 

 Plymouth were even longer. The segments, as usual in the group, are distinctly marked. 

 The caudal cup (Plate XCVIII, fig. 16 d) has a very variable outline in fresh 

 examples. Now the dorsal margin is notched with a distinct lobe on each side, whilst the 

 ventral is entire, and again a notch appears in the ventral likewise, so that four lobes 

 characterise the organ. It is therefore difficult to state that the organ in life has a 

 smooth rim, since, generally speaking, the two dorsal lobes with their white pigment are 

 conspicuous, whilst the ventral margin is even. 



Of a straw-yellow colour, rarely cream-white, with a brownish central streak 



