78 ARENICOLA BRANCHIALIS. 



This is probably the Lumhricus marinus, "another species," of Dalyell l (1853). 



Levinsen (1883) included the Arenicola branchialis of Audouin & Edwards under 

 this species, but, as shown by Ashworth, it essentially differs. 



Fauvel 2 (1899) gave a description of the structure of this form, pointing out its 

 distinctions from A marina, especially in the circulatory system and nephridia, outlines of 

 the latter in both sexes being shown. He considers the Glymenides ecandatus of Mesnil 

 and himself as the young of this species, and Ashworth agrees. It is noteworthy that 

 this form and A. branchialis have closed statocysts or otocysts with otoliths secreted by the 

 organ, whilst A. marina has ducts to its otocysts and foreign particles of quartz as otoliths. 



J. T. Cunningham 3 (1907) describes a curious Protozoan parasite (Kalpidorhynchus 

 arenicolm) occurring in white cysts in the coelom, and elongated forms attached to the wall 

 by one extremity. He refers to the gametocytes, gametocyst, and forms of gametes. 

 The spores are octozoic. 



2. Arenicola branchialis, Audouin and Edwards, 1833. Plate LXXXVIIT, fig. 9; 

 Plate CIII, figs. 12 — 12 c— bristles and hooks. 



Specific Characters. — Prostomium simple, club-shaped or truncated in front, without 

 lobes. Eyes present. Statocyst rounded, and the statoliths spherical. A pair of flask- 

 shaped oesophageal sacs. Anterior region of eleven to twelve uncinigerous abranchial 

 segments. First gill 4 on setigerous segment twelve. Five pairs of segmental organs 

 opening on segments five to nine. Twelve to twenty-eight pairs of gills, commencing on 

 the twelfth bristled segment. Gonads small. Thirty to forty-five setigerous segments. 

 No distinct tail; feet conspicuous from the branchial region to the end of the body. 

 Dorsal bristles fine, with narrow wings. Hooks with one or two spikes on the crown. 



Colour generally dark green, but also dark red or yellowish-red, with metallic lustre. 



The post-larval form has the gills, bristles and hooks extending almost to the 

 posterior end of the body ; the otocysts are closed. Five pairs of segmental organs. 



Synonyms. 

 1827. Lumhricus marinus (partim), Delle Chiaje. Mem. Anim. Invert., ii., p. 423. 

 1833. Arenicola branchialis, Audouin and Edwards. Ann. Sc. nat., xxx, p. 422, pi. xxii, fig. 13. 



idem. Hist. Nat. Litt. Fr., ii (Annel.), p. 287, pi. viii, fig. 13. 

 eine andere Art, Grrube. Anat. Physiol. Kiemenw., p. 3. 

 piscatorum (partim), Delle Chiaje. Descriz., p. 100. 

 branchialis, Chenu. Ulustr. Conch., pp. 1, 12, pi. i, fig. 6. 

 „ (near to), Glosse. Ramb. Devon., p. 174. 



„ De Quatrefages. Annel., ii, p. 265. 



„ Cailland. Ann. Sc. Acad. Nantes, xxxvii, p. 28. 



„ Johnston. Cat. Worms Brit. Mus., p. 345. 



„ {partim), idem. Ibid., p. 231. 



Grubei, Claparede. Annel. Nap., p. 296, pi, xix, fig. 2. 



1 ' Pow. Creat./ ii, p. 137, pi. xix, figs. 4—7. 



2 ' Bull. Soc. Linn. Normandie/ 5 e ser., vol. ii. 



3 'Archiv Protist./ p. 199, 2 pis. 



4 The first gill is often small, and frequently absent on one or both sides (Ashworth). 



1838. 



1841. 



1843-53 



1853. 



1865. 



1868. 



