NO. 1659. AMERICAN SPECIES OF SYNALPHEU8—C0UTIERE. 13 



This " oxyceros " form of S. lochingtoni exists, moreover, on the 

 coast of Lower California. It is at present represented only by a sin- 

 gle mutilated specimen collected by M. Diguet (Paris Museum), the 

 characters of which I believe to have specific value, and which I des- 

 ignate by the name S. paulsonoides. Compared io S. paulsoni, in- 

 stead of aS. lockingtont^ it differs by its appendages and especially the 

 third pair of feet, which are more slender. This comprises the known 

 variations in this direction, the carpocerite remaining short, with the 

 exception, of course, of S. latastei of Chile and its tenuispina form 

 from Brazil just now cited. 



The second evolutional direction (the carpocerite remaining slen- 

 der while becoming much elongate) does not appear to be represented 

 on the American coast ; on the other hand, the forms with carpocerite 

 long and swollen are predominant. S. apioceros Coutiere is found 

 here, accompanied by at least four varietal forms coming from 

 California, Florida, the AVest Indies, Venezuela, and Brazil; in re- 

 gard to the last four forms, one can not say whether the geographical 

 isolation is real, or whether it only appears so because the interme- 

 diate connectives are not known ; but the isolation of the Californian 

 form is absolute, and yet the differences which separate it from the 

 specimens from Florida are quite as slight and difficult to detect as 

 are those which separate these last from the other three forms which 

 the species assumes. While it is possible that there may be as many 

 species quite distinct and unrelated to one another, yet it is absolutely 

 undeniable that the characters of these five forms are less distant than 

 are those wdiich separate S. apioceros from S. paulsoni. Nomencla- 

 ture does not permit the expression of this, discarding (with good 

 reason) every hypothesis conveying the idea of a possible affiliation 

 between species — affiliation to wdiich the idea of these " lesser species " 

 directly leads. 



Another species with carpocerite less swollen is S. townsendi. very 

 widely distributed on both shores of America. It differs most of all 

 from the preceding in the superior spine of the basicerite being almost 

 or quite absent, so that these tw^o species show a striking parallelism 

 with S. acanthitelsonis and S. hastilicrassus Coutiere of the Mal- 

 dives. S. apioceros and S. acanthitelsonis especially differ only in 

 the angles of the telson, which are very sharp in the second species. 

 The divergence is but little greater between the two others. 



Those species with basicerite unarmed above are important from 

 another point of view, in that they permit of a passage to the 

 NEOMEms group by certain forms, such as S. paraneomeris Coutiere. 

 This species, very widely distributed from the Red Sea to the 

 Haw^aiian Islands, with several "races" (probably among them the 

 '"'■ oxyceros'''' form), differs particularly from the American &. town- 

 sendi or from S. hastilicrassus of the Maldives by the dactyls of the 



