l''>fi Prof. M'lntosh's Notes from the 



})ackward, finely tapered, the upper series long and slender. 

 The ventral lamella is a prominent, obtusely ovate process, 

 By-and-hy the superior lamella is flattened externally and 

 less free superiorly, and the ventral lamella assumes a rhom- 

 boidal outline — rounded at the inferior anjjle. The wingred 

 hooks eommence in the ventral division about the 13th foot 

 along Avith the delicate bristles, and they show a main fang 

 ■with a spike on the crown. The lamellae increase in size 

 immediately before the 50th foot, the winged hooks to the 

 number of 9 occupying nearly the entire length of the ventral 

 lamelke. 



A small form not hitherto recorded, though it has long 

 been known in Britain, is Pr/gnspio elegans, Claparede*, 

 which occurs abundantly in sandy tubes in fissures of rocks 

 and similar localities in various parts of the kingdom. The 

 head is bluntly bifid, with a median ridge running backward 

 to the second segment. The eyes are 2, 4, or 6, situated on 

 the ridge or behind the middle of the ridge and between the 

 tentacles, which are very lonj; and attenuate. The body is 

 very slender and elongate — of a dull yellowish colour with a 

 tint of orange, the anterior third being reddish from the 

 blood-vessels. The segments number from 40-60. The first 

 twelve bristled segments are narrower than the succeeding. 

 The branchia appears on the 13th segment, and to its outer 

 border the somewhat crenate lamella is fused. From 19 to 

 25 pairs of branchi?e are largely developed, with conspicuous 

 cilia in a row along the median anterior region, the rows of 

 opposite sides being connected by an intermediate line of 

 these organs. The largest branchise are about the posterior 

 third of the series, and they appear to differ from the French 

 examples, which have the branchise, according to Mesnil, 

 equally developed throughout, and that, moreover, their 

 number is usually 8, though they may reach 23. Posteriorly 

 the body terminates in 4 small whitish conical processes 

 which are not ciliated. Anteriorly the feet have conical 

 dorsal lamellse and smaller conical ventral lamellae, but the 

 latter soon diminish. The upper dorsal bristles are long and 

 finely tapered, whilst the lower and shorter have broader 

 tips with finely tapered ends. The wirier ventral forms 

 occur on the 3rd foot, as indicated by Mesnil. All the 

 bristles are dotted and curve backward. This type of foot 

 extends only to the 7th, for the 8th has its ventral bristles 

 replaced by winged hooks, about 4 of which occur on each 



* BeoTiach. p. ?,7, pi. xiv. tigs. 23-.31 (1863). 



