ARGONAUTA. 139 



orange-colored animal, finely sprinkled with purplish dots, the 

 arms 1, 2. 4, 3; the web extends along only one-half of the 

 fourth pair, and rs proportionally shorter than in A. Argo ; 

 there is also a slight difference in the arrangement of the lingual 

 denticles ; the shell is stated to be more ventricose with a dif- 

 ferent arrangement of sculpture and tubercles. Finally Reeve's 

 fig. 2 c. (fig. 121) is referred to doubtfully as an illustration. 

 The Museum of the Academy possesses a specimen from Cumaiia, 

 precisely like the above-cited figure (which represents a shell 

 from the same locality), and which is assuredly A. Argo. 



MY. Pall calls his second species A. expansa, and cites the 

 Gulf of. California as locality. He appears to have seen but a 

 single specimen, which he describes as differing from A. Pacifica 

 in having ears or lateral expansions, and in sculpture. The 

 Museum of the Academy possesses a specimen collected by 

 W. M. Gabb at San Pedro. Cal. (fig. 120), which answers well 

 to Mr. Dall's description, but is not separable from usual eared 

 forms of A. Argo. 



The Indo-Pacific A. compresxa. Bl. (A. maxima, Gualt.), some- 

 times attains a considerable size. 



I figure the Mediterranean or typical A. Argo, the auriculed 

 A. compressa, the agglutinated A. papyria and the A. ^rgo of 

 Reeve, fig. 2 c.. which may represent A. Pacifica. 



A. FRAGILIS, Parkinson. 



Shell with numerous milk-white spots. Sinus large, furnished 

 with a callus, which is attenuated towards the edge of the lip, 

 and is carried across the base of the aperture from one sinus to 

 the opposite, in a flattened arch ; upon this arch rests one side 

 of the nucleus of the shell ; which is not involuted like other 

 species, but rises in a cylindrical form, a half-inch above the 

 arcli from which the inner side springs. Around this cylinder 

 are a number of lines of growth; but it is not tubercled, and 

 has the shape of the end of the finger of a glove. 



In other respects this specimen answers to the description of 

 A. Argo. I believe it to be a pathological specimen of that 

 species. Many individuals of A. Argo show the milk-white spots 



given as one of the specific characters. 



No locality. 



