138 ARGONAUTA. 



A. XOURYI, Lorois. PI. 50, figs. 12C>. 127. 



Shell small, elongate, the sides swelled, rather closely undu- 

 lately ribbed ; carinse closely tuberculate ; the inter-carinal space 

 broad and covered with small tubercles. Greatest diameter '2 .]. 

 least 1 inches. 



Equatorial Pacific from Marquesas Isles to near Peruvian Coast. 



This species appears very distinct from all others ; it unites 

 the wide whorls and broad back of the A. hians group with the 

 fine ribs and carina-tubercles of the A. Argo group, and it differs 

 from all in its ver} 7 elongated form and the numerous tubercles 

 on the back. The latter are present on three specimens before 

 me, and are shown in one of Bunker's figures, although he does 

 not describe them. 



2. Group of A. Argo. 



A. ARGO, Linn. PL 47, figs. 111-115; pi. 48, figs. 116-119; 



pi. 49, figs. 120-123. 



Animal, body oblong, smooth; eyes large, prominent ; arms 

 unequal, order of length 1, 4, 2, 3; the dorsal pair elongate, 

 second and third pairs without any internal groove, the third 

 pair depressed their 'whole length; siphuncle united to the base 

 of the arms by a lateral membrane. 



Silvery white or yellowish or with rosy reflections, thickly 

 punctate with red. 



Shell compressed, with close prominent bifurcating ribs on 

 the sides and sharp tubercles on the keels: aperture rather 

 narrow. White, keels brownish. 



Tropical Pacific, Indian and Atlantic Oceam ; 

 Gulf of California ; Mediterranean; Cape of Good Hope. 



The obtusely angled form appears to be the only one found 

 in the Mediterranean, whilst that of the Indian Ocean (A. com- 

 presxa. 151.) is eared. Dr. von Martens mentions a ^ forma 

 wii/lufiiid-nts" represented by a single specimen in the Berlin 

 Museum, and this appears to be the same as A. papyria, Conrad 

 (fig. 119), the locality of which is not known. Mr. W. 11. Dall 

 has described two Pacific Ocean forms which I strongly suspect 

 to be identical with A. Aryo. The first, which he calls A. Pacifica 

 and which is common on the California!! coast at- times, has an 



