278 NATUEAL HISTORY OP 



3. P. STRUMA, Norman. 

 Hemescliara struma {A. M. N.). 



This is a rare deep-water species, found by tlie Rev. 

 A. M. Norman " about 25 miles north of the island of 

 TJnst." It forms yellowish glistening colonies, which 

 rise '* here and there into free frill-like expansions not 

 exceeding half an inch in height, and consisting of a 

 single series of cells." 



4. P. COMPRESSA, Sowerhy. 



Millepora cervicornis {Linn., Marsiyli), M. compressa 

 {Sowerhy), Porus cervinus {Borlase), Cellepora cervi- 

 cornis {Flem.j G. /., B. L., R, Q. C, Busk, Sars., Alder), 

 Eschara cervicornis {Busk, De Bl., D'Orh., Hincks), 

 Porella cervicornis {Gray), Eschara stellata {G.W.P.). 



Hab. : Cornwall {R. Q. C), Devonshire {Coldstream) , 

 Shetland {A. M. N.), Belfast Bay {Thompson). 



This is a deep-water species, and is known as " the 

 Stag's Horn Coralline." It grows to a height of about 

 3 inches, and forms branching zoaria of a flesh colour 

 when living. The projecting zooecia give it a roughened 

 appearance. The northern specimens appear to be 

 more slender in habit than the southern ones. 



The branches are truncate and flattened, from which 

 circumstance the specific name is derived. 



The zooecia are ovate and densely punctured. 



5. P. L^vis, Fleming. 



Cellepora Isevis {Flem., G. J., D. L., ? R. Q. G.), Es- 

 chara laevis {Sars., Alder, Smitt), E. lisse {De Bl.), E, 

 teres {Busk). 



Hab. : Shetland, and more northern waters, ? Corn- 

 wall (0. TF. P.). 



This is a very deep-water species, and, with the 

 exception of Mr. Couch (who states that it is common 



