46 Prof. M'Intosh's Notes from tie 



I 

 and the southern, -^-hich he terms ^W«« ilf-///m, H. Rathke. 

 He founds this distinction mainly on the tapering or subulate 

 condition of all the bristles (dorsal and ventral) in the 

 anterior region of Scoloplos armiyer, O. F. M., ^vhereas in 

 M hat he calls Aricia MiUleri such arc accompanied by shorter 

 blunt forms, and, moreover, in the first six segments of the 

 posterior region of the body the ventral division has two 

 protuberances below it, with a minute elevation near them, 

 and a conical papilla on the body below. It is not explained, 

 however, that a similar papilla occurs in the typical Sculo- 

 plos armiger from Greenland and the northern waters. The 

 two forms very closely resemble each other, the main fea- 

 tures which differentiate them being the somewhat longer 

 rows of ventral bristles in the southern, and the better 

 developed fleshy ridge behind them with its flattened conical 

 elevation in the ventral division, and the two papilise just 

 below it ; whilst the ventral row of bristles has a variable 

 number of short and somewhat truncate forms, which must 

 not, however, be regarded as specific. They are simply 

 modified forms of the ordinary tapering serrate kind belong- 

 ing to the division, and probably are due to the circumstances 

 of habitat, and are perhaps more abundantly present in 

 those from the Channel Islands than in the more northern 

 examples. In this form a papilla appears in the middle of 

 the fillet behind the ventral bristles of the anterior region 

 about the 5th foot, and is very conspicuous from the 10th 

 to the 13th. At the 17th foot two papillse occur, by the 

 addition of one below the median, whilst at the 18th there 

 are three, the bristles being somewhat above (dorsal to) the 

 upper. At the 19th foot the lateral ridge ends dorsally in 

 three conical processes, with a thick papilla beneath. In 

 very fine examples from Lochmaddy the papilla below the 

 foot commenced on the 15th and continued to the 2.'2nd 

 foot. 



The minute differences alluded to in the foregoing para- 

 graphs show the slender grounds on which specific diHeren- 

 tiati(.n may be founded. The divergent surroundings may 

 be accountable for some of these, and certainly many 

 examples of Scoloplos MiUleri show the cflccts of abrasion in 

 the anterior bristles of the ventral rows in the first region of 

 the body. 



In the typical Scoloplos armujcr, O. F. JM., from Green- 

 land, the fir^t fifteen anterior feet have somewhat shorter 

 (i. e. from above downwards) ventral rows of bristles. The 

 dorsal cirrus is a well-marked conical process which gra- 

 dually increases in length posteriorly. The fillet behind the 



