1890.] NATURAL SCIKNCE« OK PHILADKI>PHIA. 317 



ECHINODEKMS FROM THE NORTHERN COAST OF YUCATAN AND THE 

 HARBOR OF VERA CRUZ. 



KY J, E. IVE8. 



The Echinodermata which form the .■subject of this paper were 

 collected on the northern coast of Yucatan and at Vera Cruz, in 

 the spring of the present year, by an expedition from the 

 Academy of Natural Sciences of Philadelphia to investigate the 

 natural history of Yucatan and Mexico. The writer, who was a 

 member of the expedition, is indebted to Professor Angelo Heilprin, 

 the Director, for the opportunity of working up this portion of the 

 collection. 



The results in this department are interesting. One new genus 

 and three new species are described in the following pages, a little 

 known species is figured for the first time, the synonymy of this 

 species and of some others has. been studied with jirofitable results, 

 and the majority of the species collected supply new localities 

 which form connecting points between the northern and southern 

 portions of the great West Indian, or eastern tropical American 

 littoral fauna. 



The northern coast of Yucatan possesses a sandy beach largely 

 made up of shell fragments. The water, off the coast, is very shal- 

 low, the 10 fathom line being 20 miles from the shore, and the 100 

 fathom line about 150 miles. Three" miles off" the shore, in the neigh- 

 borhood of Progreso, the bottom is of a sandy character, although a 

 few small corals were brought up in the dredge. Along the shore to 

 the westward of Progreso is a small Serpuloid reef. Large quantities 

 of sea-weed and sponges are thrown upon the beach and lie de- 

 composing in the sun. These and numerous water- worn specimens 

 of Orhicella annularis and a large Escharine species of Bryozoan, 

 with some specimens of Xiphogorgla anceps, indicate the exist- 

 ence of a region rich in animal and vegetable life not very far from 

 the shore. The following species were collected on this coast in the 

 neighborhood of Progreso and the Port of Silam : Holothuria Heil- 

 prini, Holothuria Silamensis, Holothuria nitida, Toxopneustes varie- 

 gatus, Echinaster Brasiliensis and Luiclia alternata. No Ophiurans 

 were found on the beach, or in the dredgings oft' the shore, although 

 careful search was made for them. 



