A RETROSPECT. ix 



Sequanian of Sicily ; and the Abbe Stoppani (74) has described some species from the 

 Lower Lias of Lorabardy. 



Regarding the Echinides of Spain I have only a few remarks to make. There are 

 two works by M. Cotteau, one very short, relative to some new Echinides collected in 

 Spain by M. de Verneuil (75), and the other being a contribution to a memoir of M. 

 Barrois upon the Cretaceous strata of the Province of Oviedo, giving a description of 

 some new Echinides from the Urgonian (76). 



The Echinitic fauna from the Miocene beds of the Island of Malta, which is very rich 

 in fossil Urchins in a fine state of preservation, had been previously studied and reported 

 upon by Dr. Wright (77). These fossils were subsequently the subject of a second 

 memoir, in which are additional notes, and the description and figures of some new 

 species. In the Island of Melos a very interesting little Echinitic fauna has been 

 found, apparently of Pliocene age, and in which Herr Dames has discovered a Cidaris, 

 very different from those which now live in the Mediterranean (78). 



Before terminating my remarks relating to Europe I have still to mention a little 

 work which I have made on the Tertiary and Cretaceous Echinides brought from the 

 Crimea, by M. Ernest Eavre (79). 



Crossing now the Mediterranean to pass into Africa we arrive in Algeria, which 

 appears to be the promised land to the Echinologist, for in almost all the geological 

 formations of this region the Echinides abound in a surprising manner. M. Coquand 

 (80), in his ' Palaeontology of the Province of Constantine,' first made known a great 

 number of species. Afterwards came the large and beautiful publication of MM. Cotteau, 

 Peron, and Gauthier (81), which, commencing with the Jurassic strata, undertakes to 

 describe all the Eossil Echinides of Algiers ; this work has now reached the Senonian 

 stage of the Cretaceous deposits. Among the numerous species which these rocks 

 have yielded, the number of those appertaining to the genus Hemiaster is truly extra- 

 ordinary. In a recent work by M. Coquand (82), a great number of additional species 

 of the same genus are described, but unfortunately not figured, hence it is impossible 

 to give an exact account of the value of their characters. 



I am of opinion that a general revision of the species would result in diminishing the 

 number, for I cannot but suspect that sufficient allowance has not been made for sexual 

 differences, which are important, and which have been studied in Hemiaster cavernosus 

 living in the Seas of Kerguelen, by Sir Wyville Thomson (' Challenger, Atlantic,' vol. ii, 

 p. 229), and by Dr. Theoph. Studer (" Ueber Geschlechts Dimorphismus bei Echino- 

 dermen," ' Zool. Anzeiger,' Nos. 67 and 68, 1880). The beds in the North of Africa 

 are certainly far from being exhausted, and the Tertiary strata yet unexplored doubtless 

 contain many Echinides which by-and-by will become known. Mr. Etheridge has 

 described a new Scutelloid genus obtained from the Miocene of Morocco (83), the genus 

 Botuloidea. The Tertiary deposits of Egypt contain numerous species of Echinides, of 

 which some only have been described, and for the most part very imperfectly ; they have 



