CHONEPLAX. 59 



maculis cseruleis marmoratum; valva antica elliptica rugosa; 

 valvarum intermediarum area centralis angusta, rotundata, squamis 

 imbricatis sculpta ; areis lateralibus, sulcis divaricatis, rugosis, orn- 

 atis. Ligamento marginis fimbriato. Long. 0,040 ; lat. 0,008. 

 (Eochebr., Bull. Soc. Philom. 1881-82, p. 196.) 



Kom, New Caledonia (MM. Beaudoin and Heurtel). Not common. 

 Paris Mus. 



Cryptoplax heurteli Rochebrune. Corpus ovatum, villosum, antice 

 posticeque rotundatum ; luteo roseum fasciis 2 latis, rubris cinctum ; 

 valva antica rotundata, Isevis; valvis centralibus viridescentibus, 

 minutissimis, areis medianis Isevibus, lateralibus longitudinaliter 

 striatis, striis denticulatis. Ligamento marginis, setis longis vestito. 

 Long. 0,028; lat. 0,009. (Eochebr., Bull. Soc. Philom. 1881-'82, 

 p. 196.) 



New Caledonia (M. Heurtel) ; Rare ; Mus. Paris. 



Cryptoplax unciniferus Rochebrune. Corpus elongatum, antice 

 attenuatum, postice latum, glaberrimum, luteofuscum ; valvis 

 coeruleis, antice subquadrata, postice intense umbonate, umbone 

 acuto ; ceteris angustis, unciniferis ; area centrales minute punctata ; 

 lateralibus circulariter sulcatis sulcis imbricatis, nodosis. Long. 

 0,068; lat. 0,010. (Rochebr.'). Bull. Soc. Philom. 1881-'82, 

 p. 197. 



New Caledonia (Museum of the Colonies ; M. Heurtel). Common. 

 Paris Mus. 



Genus CHONEPLAX Carpenter, 1882. 



Clioneplax CPR. in Ball, Proc. U. S. Nat. Mus. 1881, no. 49, 

 p. 285, 288 (Jan. 20, 1882). Type C. strigatus Sowb. Chitoniscus 

 CPR. (part) 1. c., no. 49a, p. 285, 288. Types " Chitonellus striatus 

 and strigatus Sowerby, Conch. 111., figs. 62 and 63." 



Much elongated, somewhat vermiform. Valves subequal in size 

 and all strongly overlapping, the mucro of the tail valve projecting 

 far backward. Insertion and sutural plates all strongly drawn for- 

 ward, the anterior valve with 3-5 shallow slits, the other valves hav- 

 ing one slit on each side or none. Girdle minutely setose, and hav- 

 ing sutural tufts, sometimes obsolete. Gills posterior. 



Distribution, West Indies. 



This genus, whilst closely allied to Cryptoplax, differs in the strong 

 imbrication of all the valves, and their much greater comparative 



