252 PEOF. P, M. DUNCAN S BE VISION OP THE 



verse; both, the periproct and peristomial membranes largely- 

 plated near tbe test. 



JSTormal heteronomy of the right postero-lateral interradium. 



A subanal fascicle only, including a broad plastron beneath 

 tlie periproct. 



Ornamentation abactinally, in tbe interradia, of large primary 

 tubercles, slightly sunken in scrobicules, crenulate and perfo- 

 rated, scattered or in more or less wavy rows, and of close small 

 secondary tubercles and a minuter tuber culation and granulation; 

 actinally the tubercles are close and occur on the plastron. Spines 

 longest and largest on the larger tubercles, slender, pointed, 

 curved, striated ; those of the smaller tubercles are of the same 

 shape as the larger spines. 



Fossil. Tertiary ? : England, Europe. 



'Recent. Shores of N. Atlantic and Grerman Oceans, Mediter- 

 ranean, Azores, Bermuda, Caribbean Sea, Cape of Good Hope, 

 Japan ; Eed Sea ? 150 to 450 f ms. 



The definition of Loncofliorus^ which has been attributed to 

 Dames, bas not been discovered, unless Laube's definition of 

 Goncophorus, Denkschr. k. Akad. Wien, Bd. xxix. p. 36 (1869), is 

 to be taken. Dames noticed the species called Spatangus lon- 

 coplwrus, Meneg., in his description of the " Vicent. u. Yeron. 

 Tert. Ech.," Pal^ontogr. 1877, p. 83, and wondered at Laube's 

 etymology. It does not appear that a generic definition was 

 produced. 



Subgenus Loncophoeus, Dames ? 



Syn. Goncophorus, Laube. 



Spatangi without large primary tubercles on the interradia 

 dorsally. 



Fossil. Tertiary : Europe. 



Genus Maeetia, Gray, 1855 (a division of Spatangus), Gat. 



Bee. Fell. Brit. Mus. pt. i. p. 48. Loven, 1874, Etudes, 



pi. xlii. A. Agassiz, 1872-74, Bevision, p. 568. 



Test moderately thin, cordiform or ovoid, depressed, slightly 



tumid dorsally ; anterior groove slight ; posterior truncation 



narrow, actinally flat. 



Apical system slightly excentric in front, small, four close 



