Arenicola phcatbrum . 5 r > 7 



front, truncated behind, and, for the sake of description, may 

 be divided into three portions ; an anterior, which is generally 

 inflated, and always abranchial; a middle, distinguished by 

 carrying the branchiae ; and a posterior, which is both apodal 

 and abranchial, but which the species figured for the present 

 illustration proves not to be essential. At the end of the 

 anterior extremity we find the mouth, which is provided with 

 a short edentulous retractile proboscis, roughened with conical 

 fleshy papillae : there are neither eyes, nor antennae, nor cirri. 

 The feet are all similar in structure, and consist of a dorsal 

 branch garnished with proper bristles, and of a ventral ridge 

 (scarcely perceptible on the anterior segments), surmounted 

 with a series of embedded crotchets. Upon a certain number 

 of the middle and posterior segments we find highly developed 

 branchiae, fixed, like miniature arbuscules, behind the dorsal 

 branch of the foot. 



There is only one genus in this family, the Arenicola of 

 Lamarck; the name derived from arena, sand, and colo, to 

 dwell in, and very expressive of the habits of the species. 

 These may be characterised as follows : — 



1. A. phcatbrum. Branchial tufts 13 pairs ; the first six pairs of feet and 

 the tail abranchial. 



.Lumbricus punctis prominulis Lin., Faun. Suec, 364. No. 1270. — 

 Lumbricus marinus Lin., Syst., 1077.; Mull., Zoo). Dan. Prod., 215. 

 No. 2609. ; Fabr., Faun. Grcenl., 279. ; Pcnn., Brit. Zool., iv. 64. pi. 20. 

 fig. med. ; Turt., Gmel., iv. 58. ; Stew., Elem., ii. 354. ; Turt., Brit. 

 Faun., 128. ; Home, Coinp. Anat., iv. pi. 40. fig. 1, 2, 3. ; Roget, Bridgew. 

 Treat., i. 277. fig. 135. — Arenicola piscatorum Lam., Anim. s. Vert., 

 v. 336. ; Audouin and Ediv., in Ann. des Sc. Nat., xxviii. 420. pi. 22. 

 fig. 8 — 12. — Arenicole des pecheurs, Bosc, vers, i. 190. pi. 6. fig. 3.; 

 Cuv., Reg. Anim., iii. 198. — Arenicola tinctoria et A. carbonaria Leach, in 

 Supp. Encycl, Brit., i. 452. pi. 26. — Lug-worm, or Lob-worm, Provincial. 



2. A. branchialis. Branchial tufts 19 or 20 pairs; the first twelve or thir- 

 teen pairs of feet and the tail abranchial. 



Arenicola branchialis Audouin and Edwards, in Ann. des Sc. Nat., 

 xxviii. 422. pi. 22. fig. 13. 



3. A. ecauddta. Branchial tufts more than 20 pairs; the first fourteen or 

 fifteen pairs of feet abranchial, tail none. (Nova species.) 



Arenicola piscatorum is about 10 in. long, contractile, cy- 

 lindrical, the anterior and branchial portions thick and mutable 

 in form ; the posterior suddenly narrower, varying in colour 

 from a yellowish to an umber brown, sometimes glossed with 

 purple, sometimes dusky or black, the whole surface rough 

 with small granules : mouth reddish, puckered, with a short 

 proboscis closely covered with papillae; above the upper mar- 

 gin of the mouth, which projects a little, there is a small, smooth, 

 somewhat triangular, spot, with a furrow in the middle: seg- 

 ments 19 between the mouth and the last pair of branchiae, 

 as long as their own diameter, each consisting of five granulous 



r r 4 



