Boone, Echinodermata, Cruises of "Eagle" and "Ara," 1921-28 139 



References: Echinus granulans Lamarck, Anim. sans Vert., ed. 12, 



vol. 5, p. 359, 1840. 

 Echinus aequituberculatus Desmoulins, Echin. in Actes de la Soc. 



Linn. Bordeaux, t. VII, livr. IV, p. 280, 1835.— Blainville, Diet. 



Sei. Nat., t. 37, p. 86, 1830. 

 Echinus (Toxopneustes) brevispinosus Risso, Hist. Nat. de Europe 



Merid., V, p. 277, 1826. 

 Spaerechinus granulans A. Agassiz, Mem. Mus. Coinp. Zool., Ill, 



part 2, p. 452, pi. V, fig. 7, pi. VI, figs. 16-17, 1873.— Mortensen, 



Echinoderms of the British Isles, p. 309, figs. 178, 179, 180, 1927. 



Family : ECHINOMETRIDAE. 



Genus : echinometra Rondelet, Gray. 

 Echinometra lucunter (Linne). 



Plates 90 and 91. 



Type: Linne 's type is in the Coll. Lud. Ulric Reginae in the 

 Museum of Upsala, but unfortunately the labels have been lost. The 

 Twelfth Edition Systema Natura states "Habitat in O. Indico." 

 Leske's type of Cidaris subangularis came from the "West Indies and 

 is preserved at Erlangen. 



Distribution: Littoral to 8 fms. "Widely distributed from south- 

 ern Florida, the Bermudas, Bahamas, West Indies, Gulf of Mexico, 

 Caribbean Sea and northern coast of South America, down to the 

 northern mouth of the Amazon. Also with a continuous distribution 

 across the tropical Atlantic from St. Croix and Puerto Cabello to the 

 Gold Coast of Africa and St. Helena. 



Material examined: Two small specimens, collected at Dry Tor- 

 tugas, Florida, by the "Ara," Cat. no. 299. 



Color : In life the spines of this urchin are dull purplish or green, 

 the test a shade darker. Dr. II. L. Clark records specimens from 

 Antigua of a dark purple drab or violet-black; others fawn color 

 becoming purplish red at the spine tips. Still others were dark olive, 

 the primaries with purple tips. 



Habits : This urchin is said to have the curious habit of excavating 

 holes for itself in the limestone rocks, these holes being just large 

 enough to fit the urchin. It is not certainly known how it bores the 

 rock. Of more than a hundred museum specimens examined by the 

 present writer it is of interest in this connection, that none possessed 

 spines in the worn condition that might be expected, were they used 

 in excavating the rock. Is it not possible that the urchin locates a 



