dall: mollusca and brachiopoda. 227 



This indicates t,he existence of eight well-defined species of Argonauta, four of 

 •which are known to have both auriculate and simple forms or varieties. 



The data are yet insufficient to formulate the range of distribution of any of the 

 species, but they show that several of the species are apparently limited in their 

 range, two species being known from the Gulf of Panama which are unknown 

 from the Caribbean Sea or the Atlantic Ocean. 



NOTES OX THE SUMMARY. 



Tlie granulation of the surface is not a specific character in Argonauta ; all the 

 species show granulation occasionally, though with some it is more conspicuous 

 and constant than with others. 



By carefully tracing back the early names, which were nearly all based on still 

 earlier figures, I have been able to determine to which phase, auriculate or simple, 

 each name applies, which necessitates some changes from the usage current in 

 most Argonaut literature. For the convenience of the student I have noted, 

 under the letter and number of each name in the summary, tlie chief synonyms 

 in the following paragraphs. It should be noted tliat young specimens of nearly 

 all the larger forms are for a time distinctly auriculate, but may become simple in 

 the adult stage. The brown species, like A. hians, are sometimes profusely polka- 

 dotted with small round white spots resident in the shell itself and not in the 

 periostracum. 



A. A. grandiformis Perry, Conch., 1811, pi. 42, fig 4. Cape of Good Hope. This 



is A. compressa Blainville, Diet. Sol. Nat., 1820, 43, p. 212, and A. marima of 

 some authors, both based on the Cijmhium maximum striatum, etc., of Gualtieri, 

 1742, pi. 11, fig. A. So far as I have observed, none of the very large speci- 

 mens is auriculate. 



B. 1. .4. papijria Conrad, Journ. Acad. Nat. Sci. Phila., 1854, n. s., 2, p. 3.31, pi. 34, 



fig. 1 ; and A. argo agglutinans Martens, Ann. Mag. N. Hist., 1867, od ser., 

 20, p. 106. The locality is not known, but I suspect the closing up of the 

 lateral sinuses is really an abnormality. 



B. 2. .A. f y^nif.s Montcrosato, Journ. de Conchy I., 1880, 37, p. 120. Mediterranean 

 and Caribbean seas. This is ihe/ormu ol'tusaiigula of von Martens. 



B. 3. A. (irgo (Linno, \1^8, ex parte) Bolten, Mus. Bolt., 1798, p. 70, no. 905; + 

 A. sulcata Lamarck, Syst. An. s. Vert.. 1801, p. 99 ; -f -1. papi/raceu Link. 

 Beschr. Rostock Saminl., 1807, p. 85 ; -I- .^4. argn Lamarck, An. 8. Vert., 1822, 7, 

 p. 652 ; Blainville, Diet. Sci. Nat., 1826, 43, p. 212 (after Cgmbium tenue Gual- 

 tieri, 1712); + ^1. hnnstntm Dillwyn, Kec. Siiells, 1817, 1, p. .335 (testa 

 junior); + A. navifhrmis Conrad, Journ. Acad. Nat. Sci. Phila., 1854, 2d 

 ser. 2, p. 334. Mediterranean. 



The Mediterranean form was early selected from amongst the heterogeneous 

 assembly contained in the Argonauta argo of Linne and the older authors. Mar- 

 tini's figure 157, referred to by Bolten, shows only moderate auriculation, which is 



