45 



in front, flattened throughout the rest of its exterior, and pro- 

 portionally broad. In life, it must have been finely coloured, 

 for in spirit the anterior region is dappled with reddish brown, 

 and iridescent. 



The branchiae commence on the 19th foot, or in others on 

 20th and 2ist feet, as a simple filament, thus corresponding 

 in origin with those of Marpliysa sanguinea from the Channel 

 Islands and southern Europe, and, as noted subsequently, their 

 condition on corresponding feet is similar. No example was 

 complete, but, as far as could be observed, their distribution 

 posteriorly was similar. 



At the loth foot, the dorsal cirrus is proportionally shorter 

 and stouter than in Marpliysa saiigninca, and there are live 

 black spines in the setigerous region, instead of three. The 

 simple dorsal bristles are similar in both, and no appreciable 

 distinction betw^een the ventral bristles, except in size, in the 

 respective forms is noticeable. The ventral cirrus is slightly 

 more prominent in the British form. The foot remains the 

 same till the appearance of the branchiae — often posterior to 

 the 20th foot. At the 30th foot, whilst Marphxsa sanguinea has 

 two long slender divisions of nearly equal length to the 

 branchia, and the dorsal cirrus is slender, the African form has the 

 gill much shorter — the longest not being more than twice 

 the length of the dorsal cirrus, the shorter about the same 

 length. Four divisions of the branchia occur in the 50th foot 

 of the British form, and they are nearly of equal length — two 

 arismg distally, and two beneath (externally) ; the African has 

 also four divisions — two terminal, and two external. The pro- 

 portions of the other part of the foot are the same. In each, 

 four divisions of the branchia occur in the 70th foot. 



So far as can be observed, both from the external appearance 

 and the minute structure of feet and bristles, as well as of the 

 dental apparatus, the British and tlie South African forms are 

 the same. The species stretches to the American shores of the 

 Atlantic, having been found on the coast of Rhode Island and 

 New Jersey by Leidy,* by Websterf further south on the Vir- 

 ginian shores, and he states that it is common, especially near 

 high water-mark. He points out that De Quatrefages made a 

 new species {Marpliysa Leidii) of Leidy's examples, having, by 

 mistake, changed the 16 of the American authors' description 

 into 60. Alarenzeller,! again, finds the same species at Angra 

 Pequena, on the south-eastern coast of Africa. 



* Jour. Acad. Nat. Sc. Philad. ii., Vol. iii., p. 147. 

 t Trans. Albany Inst, ix., p. 36 (sep. copy). 

 X Zool. Jahrb. iii., p. 11 (sep. abdr.). 



