TOXOPNEUSTES VAKIEGATUS. 299 



More abundant material collected by the Thayer Expedition from St. 

 Thomas, Rio Janeiro, and along the whole coast of Brazil by Messrs. Allen 

 and Hartt, by Mr. Bickmore at the Bermudas, and by Mr. Pourtales, in the 

 Deep-Sea Dredgings of Florida, reduces the number of species of this genus, 

 which had been distinguished by my father and myself to the original E. varie- 

 gatus of Lamarck. The extensive series of large specimens brought to the 

 Museum by the Thayer Expedition, collected at every point from Rio as far 

 as St. Thomas, shows an extent of variation which is most surprising, while 

 the young specimens collected by Pourtales show an equal variability, leav- 

 ing none of the characters upon which Lytechinus carolinus or Lytechinus 

 atlanticus had been established as sufficiently permanent to warrant their 

 separation from Lytechinus variegatus. Yet, as is generally the case in 

 species of extensive geographical range, we find a few features which seem 

 to characterize the majority of specimens found at different localities, while 

 others again have such combinations of characters as show unmistakably 

 the gradual transition of all the features by which these so-called species 

 have been distinguished. The specimens from South Carolina, Georgia, and 

 the shores of both sides of the peninsula of Florida, as well as Alabama and 

 Louisiana, usually possess slightly stouter spines, a somewhat thicker test, 

 and larger tubercles. Those of West India Islands, as well as the south shore 

 of Cuba, have a thinner test and rather more elongate spines. The speci- 

 mens from the Bermudas have more closely crowded tubercles and slender 

 spines. In the specimens collected by Mr. Pourtales at thirty-four fathoms, 

 we find slender spines and the primary tubercles far apart, leaving the test 

 quite bare, when compared to the average of specimens of the same size of 

 various localities. But when we take the series from Brazil, of which we 

 have by far the greatest number, we find all these various characters com- 

 bined alternately so as to leave no doubt that we have but one species ex- 

 tending from Rio Janeiro along the whole coast of Brazil, to the West India 

 Islands, the shores of the Gulf of Mexico, Cuba, Florida, Georgia, South and 

 North Carolina. Those features which are usually well marked as specific 

 differences — the structure of the scales on the actinal membrane, the pedi- 



