04 Prof. M'lntosli's Notes from the 



chambered by a series of larger reticulations, which cause 

 it to resemble crocodile leather. An account of this form 

 was 2:iven by Dr. Erik Nordenskiold. 



The fourtli species, Petta piisilla, Malmgren, frequents, as 

 a rule, deep water off the English, Scottish, and Irish coasts. 

 The crown has eleven palcoke on each side with a pale base, 

 ■which is expanded at the end ; the shaft being flattened, 

 little dilated, and then tapered to a blunt (rounded) point. 

 In developing paleolae a translucent process passes from the 

 blunt tip. The blunt points of tliese and the coarser nature 

 of the tube, as compared witli Lacjis koreni, are interesting. 

 Tlie upper area obliquely slopes backward and has a smooth 

 edge without a rim. It extends to the ventral edge of the 

 paleohe, where it ends at the anterior cirrus, a smooth area 

 occurring belovv the paleolie — that is, between them and the 

 veil. This process is clearly a development of the flattened 

 area of the crown, and is independent of the veil. The 

 latter has a high arch and a smooth border, but in two 

 examples the highest point of the arch had three papillae 

 close to each other, the rest of the margin being quite 

 smooth. The veil is of moderate breadth, is attached to 

 the roof of the oral region, and gives origin to the 

 tentacles, which form the usual lateral groups and have the 

 typical structure. 



From the second cirrus a ridge passes, as in other forms, 

 veutrally on each side. In this species the anterior margin 

 is 4- or 5-dentate, whilst in the centre is a deep hiatus. 

 In small examples the processes are slender tapering papillae. 

 The branchiae on the next two segments are typical. 



The second region corresponds with that in other forms, 

 viz. has more slender bristles in smaller tufts than the suc- 

 ceeding. Their structure, however, including the poste- 

 rior series, corresponds with the type common to all. The 

 stout simple bristles are tapered distally aiul have traces of 

 wings; and the others have a spear-head enlargement at the 

 end of the shaft and a tapering tip, but the enlargement is 

 projjortionally broader and the tapered tip shorter than in 

 allied forms. In the posterior region the fourteen pairs of 

 bristle-bundles exhibit a gradation from the anterior to the 

 posterior extremity. jNlorcover, the region is only a little 

 tapered posteriorly, the termination being (uunparatively 

 broad. In consequence, the caudal appendix projects little 

 veutrally from the truncated end of the body, tlie last foot 

 being modified into a rounded flattened lobe projecting 

 beyond the truncated surface and with a subulate cirrus at 

 its extrcmitv. Moreover, the sonu'what long low of caudal 



