SILIQUARIA. ANNELIDES. 135 



Gen. 12. SILIQUARIA, Lam. Serpula, Lin. 

 Shell tubular, irregularly twisted, attenuated posteriorly, some- 

 times in a spiral form at the base, and open at the anterior 

 extremity, with a longitudinal subarticulated cleft, which runs 

 along its whole length. 



S. anguina, Lam. Shell rather taper, somewhat spiral, with a lon- 

 gitudinal subarticulated fissure. 2 to 8 inches long, and five to 

 eight lines in diameter. Indian seas Born. Mus. pi. 18, fig. 15. 



S. muricata, Lam. Shell angular, muricated, with a longitudinal 

 fissure ; the ribs with hollow scales ; colour reddish white. In- 

 habits Indian seas. Rumph. Mus. pi. 41, fig. H. 



Gen. 13. ARENICOLA, Lam. 



Body soft, long, cylindrical, annulated, naked posteriorly, with 

 bundles of bristles in two rows in the middle and anterior 

 part ; branchiae external, in tufts or branched, in the middle 

 portion of the back, and under the fasciculi of bristles ; mouth 

 terminal, naked ; no eyes. 



A. piscatorum, Lam. ( Lumbricus marinus, Lin.) Body circular, 

 annulated, with greater and lesser rings, on each of which are two 

 tufts of short bristles ; mouth round. Sandy shores of Europe, and 

 much used as a bait for fish Penn. Brit. Zool. iv. pi. 20. fig. 3. 



ORDER IL ANTENNAT^E. 



Head antenniform, furnished with eyes ; a protractile proboscis 

 often armed with jaws ; and setiferous retractile pediform pa- 

 pillae ; branchiae disposed longitudinally. 



All the animals of this order have a head constituted by a slight anterior inflation of 

 the body, which bears the antennae and eyes. The antennae are to the number of 

 five ; but these are not always found at the same time. The pediform papillae are re- 

 tractile, setiferous, and disposed in lateral rows. Each foot is divided into two parts, 

 one dorsal, the other ventral, and each part has a bundle of subulate bristles and a 

 cirrus. They have, besides, very often one spine, and sometimes many ; but in some 

 genera these are wanting. The eyes are to the number of two or four. The mouth 

 is an exsertile proboscis, generally withdrawn within the body when the animal is 

 not using it, and often armed with jaws. The Annelides of this order are nu- 

 merous, all marine, and the greater part have in some sort the appearance of Scolo- 

 pendrae. M. Savigny divides this order into four families, viz. Amphmomce, Eunicce, 

 Nereides^ and Aphroditce. 



SECTION I. 



Branchiae in the form of complicated leaves or tufts, or very 

 ramose, always large and apparent ; no spines. 



FAMILY I. AMPHINOM^:. 



Branchiae and cirri superior, at all the pairs of pediform papil- 

 lae ; no jaws. 



