188 BULLETIN OF THE 



it is quite remarkable that only single specimens of the two most 

 common species of Echini of that coast, Strongylocentrotus albus and 

 Arbacia nigra, were brought home. 



No species hitherto not noticed from the west coast of Central 

 America, Mexico, or the Gulf of California, or San Francisco, were 

 collected. 



During the visit made to Juan Fernandez a few Echini were col- 

 lected ; among them specimens of a small Spatangoid (Nacospatangus 

 gracilis A. Ac.) allied to Micraster and Spatangus. Small specimens 

 of Echinus margaritaceus were also collected there ; other specimens 

 of the same species were obtained off Cape Dos Bahias, on the east 

 coast of Patagonia. A fine specimen was in the Museum collection 

 previously, from Cape Horn. 



A full description and figures of the most interesting species will be 

 given in the Zoological Results of the Hassler Expedition. 



Paleopneustes cristatus A. Ag. (nov. g-r-n. ctsp.) 



Seen in profile this species has a remarkable resemblance to some of the 

 forms of Ananchytes ovata. Like it, it has neither peripetalous nor anal 

 or subanal fascioles. The actinal surface is nearly flat, the anterior ex- 

 tremity rounded, with no trace of indentation for the anterior ambu- 

 lacrum, which consists, as in Ananchytes, of slightly diverging zones, with a 

 pair of pores piercing the centre of each ambulacral plate. The abactinal 

 svstem is, however, compact, as in Spatangus, and the lateral ambulacra 

 form imperfect petals, diverging, extending half-way from apex to edge of 

 the test, terminating abruptly, and very slightly depressed below the level 

 of the test. The vertex corresponds to the apical system, and is nearly 

 central. The anal system is large, circular, and placed close to the edge 

 of the test in the truncated posterior extremity of the test. The lateral 

 petals are continued by distant pairs of pores in the centre of the ambu- 

 lacral plates to the actinostome. The actinal ambulacra form broad avenues 

 on each side of the triangular elongate plastron. The actinostome is trans- 

 verse, narrow, with a very prominent posterior lip. The upper part of the 

 test is covered by distant tubercles of uniform size, arranged in regular 



