St. Andrews Marine Laboratory, 485 



that of the process, and especially abound towards the base of 

 the filament, which thus is more rigid and tougher than the 

 distal region, into the composition of which mud, sand, and 

 the secretion chiefly enter. In consequence of this structure 

 the distal region slightly curves downward in the ordinary 

 position in the water, while the proximal stands stiffly out- 

 ward. These processes are generally fixed to the main stem 

 of the Tuhularia^ though occasionally they spring from the 

 tip of a young example attached to the former, or stretch from 

 the extremity of a parasitic Sertularian. 



These filamentous processes are usually at some distance 

 from the nests or tubes of the Crustaceans, which climb 

 actively on them. Whether they thus give them a larger area 

 for the capture of prey in security or afford a more extensive 

 surface for the temporary arrest of minute larval or other 

 forms on which they feed is unknown. It is probable, how- 

 ever, that processes so elaborate subserve some useful purpose 

 to the species, and are not the result of mere purposeless 

 formation by way of exercise. 



Spinous processes of an equally peculiar kind are not un- 

 common on the tubes of annelids, such as those of Nothria 

 Willemoesii and certain Terebellidee discovered by the ' Chal- 

 lenger.' Most of these, however, have a protective function, 

 whereas the foregoing processes cannot have this use assigned 

 them. 



4. On certain Structures resembling Ova procured 

 off the Forth. 



When carrying out the work for H.M. Commission on 

 Trawling an old willow basket came up in the net on the 

 15th August, 1884, 15 miles S.E. of the island of May, 

 which, besides other interesting marine forms, had attached 

 to it certain peculiar dull yellowish structures resembling ova, 

 and about |- inch in diameter (PL XIII. fig. 10). They adhered 

 to each other, forming a group in a single layer along the bark 

 of the twig. They are nearly circular, with a short, slightly 

 curved distal process. The capsule is yielding, but tolerably 

 tough, and the contents consist of a structureless soft and cohe- 

 sive gelatinous substance of a pale colour. They were kept for 

 a considerable time in the marine laboratory of St. Andrews, 

 but no change ensued until decomposition set in. 



5. Note on a Female Porpoise and its Milk. 



Amongst the porpoises examined during the year at the 

 marine laboratory was a fine adult female abounding in milk. 

 For some days before its capture, in August, a solitary adult 



