432 Dr. Johnston on the British Aphroditacea. 



yields in strength and longitude to the palpi. The mouth has 

 a projectile proboscis with a circle of little tentacula round its 

 orifice and four large horny jaws curved at their points. The 

 scales or elytra are always exposed, and are very variable in 

 number, but the first twelve pairs regularly alternate with the 

 superior cirri on the twenty-three first segments, and if more 

 elytra exist they alternate in a different series, or on every 

 third segment : they are lamellar or sometimes vesicular, and 

 either smooth or covered with little granulations. The branchiae, 

 which are simple and obscure, exist only on the non-elytrous 

 feet, and follow consequently the same alternating order. The 

 feet are bifid, but the superior branch is small and almost con- 

 fluent with the inferior, which is greatly developed. The su- 

 perior cirri are long, the inferior short and conical : the bristles 

 of the superior branch short and almost always slenderer than 

 those of the inferior, subulate and smooth at the point, or like 

 the inferior bristles, somewhat thickened and serrulate along 

 the edge. The spines present no peculiarity. The first pair 

 of feet are destitute of bristles, but are terminated by two 

 long tentacular cirri, which advance on each side of the head 

 and resemble antennae ; while on the last segment we find 

 filiform appendages formed by a nutation of the superior cirri, 

 and constituting in general terminal styles. 



* Scales immovably fixed. 



1. P. squamata, scales twelve pairs, ovate, imbricate, gra- 

 nulous, ciliated on the external margin. Plate XXII. fig. 1. 



Aphrodita squamata, Lin. Syst. 1084. Pallas Misc. Zool. 91. tab. 7. fig. 

 14. a — d. Bast. Opnsc. Subs. ii. 66. pi. 6. fig. 5. Pen. Brit. Zool. iv. 

 tab. 25. fig. 2. Turt. Gmel. iv. 80. Steiv. Elem. i. 387. Turt. Brit. 

 Faun. 136. — Aph. scabra, Penn. Brit. Zool. iv. 88. Turt. Gmel. iv. 80. 

 Stew. Elem. i. 387. Turt. Brit. Faun. 136. Jameson in Wern. Mem. 

 i. 557. — Aph. pedunculata, Pen. Brit. Zool. iv. 87. tab. 26. fig. 2, — 

 Aph. longirostra, Brug. Encyclop. Meth. vi. 86. Bosc Vers, i. 182. — 

 Aph. clava? Montagu in Lin. Trans, vs.. 108. tab. 7. fig. 3. — Aph. 

 punctata, Bosc Vers, i. 182. Jameson in Wern. Mem. i. 558. — Polynoe 

 squamata, Lam. Anim. s. Vert. v. 309. Stark Elem. ii. 139. Audouin 

 and Edwards in Ann. des Sc. Nat. xxvii. 416. pi. vii. fig. 10 — 16. — Po- 

 lynoe scabra, Johnston in Zool. Journ. iii. 331. 

 Hab. In deep water, frequent on the coast. Brighthelmstone and An- 



glesea, Pennant. Leith shore, and Orkney and Shetland Islands, Prof. 



Jameson. Berwick Bay, G. T. 



