140 NOTARCHUS. 



tinct neck, and furnished with four elongated, linear, distant tenta- 

 cles, more or less ornamented with papillae, mouth beneath, the lip 

 dilated laterally into an acutely conical process, like a third pair of 

 tentacles. ( Old.) 



The papillae on the mantle are capable of being individually 

 elongated and contracted, as they are in Cypraea. 



Distribution, Indo-Pacific region. These animals live on floating 

 sea-weed, away from the shore. The exact status of the group, and 

 its relation to Notarchus and Aclesia, can be ascertained only by 

 more exact investigation of material. I have seen none of the spe- 

 cies. 



Most described forms are decorated with ocelli or eye-spots, and 

 all but N. longicauda have simple or branching processes of the in- 

 tegument. In alcoholic specimens the lip-processes characteristic of 

 the group are sometimes retracted ; but they are never so strongly 

 developed as in Aclesia. 



N. LINEOLATUS Gould. PL 29, figs. 37, 38, 39. 



Length three and a half inches. Animal elongated, delicately 

 attenuated posteriorly, of a pale grass green color, ornamented with 

 longitudinal, parallel, contorted, rusty lines, and scattered ocelli of 

 unequal size. The papillae of the man tie are branching. The ante- 

 rior tentacles are short, tapering, and destitute of papillae. (Old.). 



Honolulu, Oahu, on a coral reef. 



Stylocheilus lineolatus OLD., U. S. Expl. Exped., Moll., p. 225, pi. 

 16, f. 270, a (1852) ; Otia Conch., p. 227. 



Dr. Pickering, who observed this animal, remarks that the creep- 

 ing disk is very long, ending in a sharp point. Branchial cavity 

 generally kept pretty wide open ; the branchiae are very large, not 

 covered by a dorsal plate, and colored above in the same manner 

 as the mantle, and they are inflated as though injected with water. 

 The heart is seen beating on the left side, immediately under the 

 origin of the branchiae. The vent projects much as in Doris. The 

 lines on the surface were more or less concentric, like the striae in 

 the palm of the hands. Motion quite active. 



Though the two figures differ somewhat in their details, I judge 

 them to represent the same species. In the dark green one, the 

 tentacles are shorter, and the cephalic pair are destitute of papillae, 

 and the papillae are branched. In the pale one (fig. 37), the ten- 



