142 Dr. W. C. Mcintosh oji the Invertebrate 



as at Cliff Sound and bet\veen the Burras, where the still sea- 

 water is bridged by a single arch of a few feet. To represent 

 the ^ostera-fields of the west and south there are but a few 

 Conferva^ Ulvce^ and Porphyrce attached to stones on the flat 

 surfaces of the beach. The calcareous rocks of the south, and 

 the multitudes of worm-eaten boulders scattered on many- 

 parts of the shore, as in the Isle of Wight, form likewise a 

 boldly marked contrast. 



Within reach of the modern tide, also, it is interesting to 

 find the remains of oceanic animals long since extinct — to see 

 Actiiiia mesemhryanthemum attached to a mass of encrinite 

 stalks, Litorina rudis in groups on Li«^ii?a-shale, and the 

 white coils of Spirorhis incrusting a nodule containing a 

 fossil fish. Yet these features do not appear much out of 

 place near a city whose pier is to a considerable extent con- 

 structed of the fine old stones and ancient oak which once 

 formed part of the splendid pile of its cathedral. 



On the whole the zoological features of St. Andrews are 

 northern. 



Subkingdora PROTOZOA. 

 Class RHIZOPODA. 



Order Spongiadae. 



The Sponges of St. Andrews are, perhaps, the least-inves- 

 tigated group, partly because a collection carefully made many 

 years ago has been lost. In looking over those obtained since. 

 Dr. Bowerbank has most kin<^ly given his experienced aid in 

 doubtful cases ; and the description of the new species is solely 

 his. The littoral forms are scattered in considerable profusion 

 between tide-marks under ledges and stones, sometimes near 

 high-water mark. Indeed, in the higher pools and tide-runs 

 in the latter region they are often peculiarly luxuriant. The 

 brightly coloured Halisarca^ so abundant on the under surfaces 

 ot stones in the Hebrides, and the rarer botryoidal Tethea are 

 unknown at St. Andrews, as are likewise the cup and tin-nip 

 sponges of the Zetlandic seas. The greater luxuriance of the 

 ubiquitous Halichondria panicea on the stems of the Lami- 

 narifB further characterizes the coast of the extreme west ; 

 and the decay of the seaweed often leaves tubes of sponge 

 from a foot to eighteen inches in length. In like manner the 

 greatly increased size of Grantia ciliata^ the vast abundance of 

 Hymeniacidon celata, its beautiful arborescent patterns in the 

 tide-worn shells, and its perforations in the limestone rocks are 

 diagnostic of the warmer waters of the southern coast. 



