24 OPHELINA. 



Dujardin 1 (1839) considered that this form, his Nats jncta, belonged to the same 

 group as Nais digitata, as having eyes, not only in their usual position, but along the body. 

 His description and figures are quite recognisable. 



Grube (1851) placed this form along with the genus Dew. His later view that 

 Polyophtlialmus is only a genus of the OpheliidaG would appear to be reasonable. It is, 

 further, interesting to note how closely the structure of the body-wall in Polygordius 

 approaches that in the present group, as shown long ago, 2 and as De St. Joseph more 

 recently corroborated. 



Claparede (1864) gave a detailed account of this species from Port-Vendres, his view 

 being that it formed a special type characterised by the muscular bands which divide the 

 ccelom into three spaces, and by the presence of the cephalic pouches (grooves). The 

 muscular bands, however, appear to be only the oblique muscles. 



De Quatrefages 3 (1865) describes the head as of three lobes, and Carus (1885) follows 

 him, but, as Grube pointed out, this is a misapprehension. 



E. Meyer 4 (1882) gives a careful account of the small and simple " Seitenorgane " of 

 this species. He also describes a structure like a cardiac body in the heart, but, as it is 

 fastened to the intestinal epithelium, there is doubt as to its exact nature. The segmental 

 organ opens just above the lateral (corporeal) eye-spot. His figures are excellent. 



Lessona 5 (1 884) gives a careful structural description of this form, especially of the 

 nervous system, eyes, and sense-organs. He shows no hypoderm between the cuticle and 

 the ganglia of the cord. His lateral organs of sense recall those of larval fishes. 



De St. Joseph (1898) thought that it is probable, as Monticelli holds, that P. Ehren- 

 bergi, De Quatrefages, P. dnbius, De Quatrefages, and P. pallidus all pertain to this 

 species. The same author 6 (1906) describes the body as pale or clear brown with mosaic 

 patches of brown grains on the dorsum and sides throughout. The number of anal 

 papillae is from eight to ten, and of the lateral eyes from ten to sixteen. 



Fauvel (1907) considers P. Ehrenbergi and P. dubius of De Quatrefages and 

 P. pallidus of Claparede as the same form. 



Genus LXXXIV.— Ophelina, Hansen, 7 1882. 



Cephalic region produced into a long tapering snout with a terminal enlargement like 

 a probe-point. Lateral projections in place of the nuchal pits. Body resembles that of 

 Ammotrypane in regard to bristles and cirri. Anal scoop rather long, with a few terminal 

 cirri. 



1 'Ann. Sc. nat./ 2 e ser., t. xi, p. 293, pi. vii, figs. 9—12. 



2 'Ann. Nat. Hist./ ser. 4, vol. xvi, p. 369. 



3 'Anneles/ t. ii, p. 203. 



4 'Arch. f. ffiikr. A nat./ Bd. xxi, p. 791. 



5 'Mem. Accad. Torino/ ser. 2, t. xxxv, p. 309, tav., figs. 1-15. 

 s 'Ann. Sc. nat./ 9 e ser., t. iii, p. 232. 



7 Hansen applied the name to two forms procured during a voyage to Brazil and La Plata. 



