3(Jo Dr. Johnston on the British Annelides. 



XLIII. — Miser/ Ian ca Zoologica. By George Johnston, 

 M.D., Fellow of the Royal College of Surgeons of Edin- 

 burgh. With Plates X. and XI. 



[Continued from p. 232.] 



British Annelides. 



In the month of June of the present year, Mr. Edward Forbes, 

 accompanied by Mr. Goodsir, visited the islands of Orkney 

 and Shetland, with a view to the investigation of the marine 

 zoology of the northernmost district of Britain*. The An- 

 nelides which were collected during this tour, Mr. Forbes, 

 with a liberality I am most anxious to acknowledge, entrusted 

 to my examination ; and I am now about to give the result 

 of it to the public, in the hope that this may interest such 

 naturalists as devote themselves to the study of our native 

 Fauna. 



Of the Aphroditacea, there were, in this collection, speci- 

 mens of Aphrodita aculeata in a young state ; of an Aphro- 

 dita nearly allied to the A. hystrix of Savigny ; and of my 

 Sigalion Boa. The new Aphrodita belongs to the section of 

 the genus that is distinguished by having the scales or elytra 

 naked or uncovered, and is the first British example of the 

 kind. The specimen presented to me is 14 lines in length, 

 and 4 in its greatest breadth : the body is elliptical, rather nar- 

 rower posteriorly than in front, of a uniform greyish white 

 colour, somewhat hairy and hispid on the sides from the va- 

 rious bristles which garnish the feet. (Plate X. fig. 1, 2.) The 

 scales form a series on each side ; they are roundish, smooth, 

 thin and flexible, vesicular in the specimen, probably from im- 

 mersion in the spirits ; there are 15 pairs of them, but the 2 

 first pairs and the 3 caudal ones are so small as to be easily 

 overlooked. The head (fig. 3.) is entirely concealed under the 

 front scales. It is furnished with two proportionably large 

 setaceous smooth palpi, approximated at the base, but I was 

 not able to detect any antennae. The mouth (fig. 4.) is infe- 

 rior, large, circular, puckered, armed with a strong retractile 

 proboscis, the orifice of which is encircled with a row of ten- 



* See the Athenaeum, No. 618, p. 647. 



