Verrill, Kotes on Madiata. 311 



Astriclypeus Verrill, gen. nov. 



Ambulacral star as in Encope; four genital openings, tlie posterior 

 one wanting, as in Mdllta; with five lunules or perforations in the 

 prolongations of the ambulacra, as in Encope; but destitute of any 

 perforation or indentation in the posterior interambulacrum, like 

 Lobophora. Anal opening round, about midway between the mouth 

 and margin. Sulcations of the lower side more simple than in Encope, 

 a primary branch passing along close to the openings, on each side, 

 and sending off numerous inconspicuous branches to the interambul- 

 acra. Actinal opening as in Encope. 



Tliis genus presents a remarkable combination of characters belong- 

 ing to other allied genera, but has an assemblage of characters entirely 

 unique. It appears to be most nearly allied to Lohophora, from which 

 it differs chiefly in possessing five ambulacral lunules or openings, 

 instead of but two ; and in the sulcations of the lower surface. 



Astriclypeus Mannii Verrill, sp. nov * 



Test subcircular, about as long as broad, with the posterior side 

 slightly truncate, and a slight prominence of the edge opposite each 

 oiDcning. Summit central, considerably elevated. 



Length 4*2 ; breadth the same ; height '65 ; from center to anterior 

 opening 1*2; to the lateral ones I'l; to end of anterior ambulacral 

 ray 1*2 ; to lateral '98 ; breadth of anterior ambulacral ray '42 ; of its 

 median area '16 ; of the anterior lateral '45 ; its median area "2 ; length 

 of three anterior openings "6; breadth 'IS; length of posterior open- 

 ings '7; breadth 'IS; center of mouth to anal opening 1 inch; from 

 the latter to the margin the same. 



The anterior ray of the ambulacral rosette is a little longer and 

 narrower than the others, with the widest part near the end, which 

 is not closed ; lateral rays nearly equal in length, the anterior pair a 

 little wider, increasing in width to near the end, which is broad and 

 rounded. Openings oblong, the posterior pair a little longer. Anal 

 opening nearly circular, midway between the mouth and margin. 



Locality West Coast of North America (?). (Japan, — Reprint). 



The single specimen of this curious species was presented by Mr. 

 Horace Mann, of Cambridge, Mass., in honor of whom I have named 

 it. It was obtained by him, with several other West Coast Echino- 



* Dr. F. H. Troschel has well described and figured this species under the name of 

 Crustulum gratidans in Niederrh. Geaells. fur Naturg. und Heilkunde, Universitat Bonn, 

 Aug. 3, 1868, p. 1, PL I. In Archiv fur Naturg. 1869, p. 52, he has identified it with 

 our species and described specimens from Japan (E. von Martens), — Reprint. 



TR.A.NS. Connecticut Acad., Vol. I. 40 June, 1867. 



