Dr. Johnston on the British Aphroditaceee. 429 



of them, and the thirteenth are always attached to the feet of 

 the twenty-fifth segment, — the pairs which precede this * al- 

 ternate on every other ring with the superior cirri, and the 

 pairs which succeed it are placed on every third ring. The 

 branchiae consist of tubercles sometimes indistinct, often 

 broken on their edges, disposed in transverse rows, and, like 

 the dorsal cirri, they cease to appear and disappear alternately 

 posterior to the twenty-fifth pair of feet : they sometimes differ 

 very little from the protuberances which afford attachment to 

 the scales. 



1. A. aculeata, scales concealed, blotched with black; hair- 

 like bristles green and golden, the spine-like bristles dark 

 brown. Sea Mouse. Plate XXI. 



Eruca marina Rondeletii pilis in dorso instar Colli Columbini variegatis, 

 Sib. Scot. III. pars sec. lib. iii. p. 32. Scolopendra marina, Molyneux 

 in Phil. Trans, abridg. iv. 133. and 368. pi. 3. fig. 6, 7. — Aph. nitens, 

 Lin. Faun. Suec. 367. no. 1284.— Aph. aculeata, Lin. Syst. 1084. 

 Pallas Misc. Zool. 77. tab. 7. fig. 1 — 13. Bast. Opusc. Subs. ii. 62. 

 pi. 6. fig. 1—4. Pen. Brit. Zool. iv. 86. tab. 25. fig. 1. Mull. Zool. 

 Dan. prod. 218. no, 2641. Turt. Gmel. iv. 79. Slew. Elem. i. 387. 

 Turt. Brit. Faun. 136. Home Comp. Anat. pi. 39. fig. 1, 2. Blumenb. 

 Elem. Nat. Hist. 245. Jameson in Wern. Mem. i. 557. Bosc Vers, 

 i. 181. Cuv. Reg. Anim. iii. 206. Audouin and M. Edwards in Ann. 

 des Sc. Nat. xxvii. 402. pi. 8. fig. 7. Edin. Journ. Nat. and Geogr. Sc. 

 iii. 51. Roget Bridgew. Treat, ii. 102. and 298. — Aphrodite herissee, 

 Brug. Encyclop. Meth. vi. 85. — Halithea aculeata, Lam. Anim. s. Vert. 

 v. 307. and 2de edit. v. 542. Risso VEurop. Merid. iv. 412. Stark 

 Elem. ii. 140. Edin. Journ. Nat. and Geogr. Sc. iii. 246. 

 Hab. Common on most parts of the British coast. Found at Leith, Sit 

 Robert Sibbald. Coast of Berwickshire, not common. 



Desc. Body from three to five inches long, oval, narrowest 

 behind, convex dorsally, the back of an earthy colour, rough- 

 ish with a thick close felt of hair and membrane forming a 

 sort of skin which entirely conceals the scales, the sides 

 clothed with long silky green and golden hairs clustered in 

 fascicles and glistening like burnished metal, with blackish- 

 brown spin iform bristles intermixed: ventral surface flat, often 

 light coloured and dotted, sometimes dark brown, obsoletely 

 ribbed across. Read small, entirely concealed, roundish, with 

 two round clear spots or eyes on the vertex : antennce minute ; 

 * The fourth and fifth segments, however, are both squamiferous. 



