350 



A. E. Vcrrill 



Cnist<i<-<-<i of Bcrnnnli. 



The type, which is the only -prciincii known, \\:i- caught in a 

 baited fish trap in Harrington Sound, in shallow waler, April, I'.nii. 



The specimen which approaches most nearly to the typ.-of tins 

 variety is .1 east shell, found on the shore (li-. ] :. ) ami of which only 



the carapace was preserved. I have included its measurement with 

 variety (>/ xn*. however, as a matter of con\ eiiience. though it differs 



from that in having larger ami v Bquarrose marginal teeth, of which 



the sccoml ami thin] are ol.t iisely roiimle| ; ami in having a proin- 

 ineiit ami distinctly 4-lobed front, as in niiit<i.<\ from which it differs, 

 therefore, chiefly in the shorter -re. .ml ami third teeth, ami the nar- 

 rower ami more rounded carapace. The Hanks were convex ami the 



Figure 15. 



Phot. A. H. V. 



H,,-l>sHi \.-iricty iniixi.i-. < ';ira|p;ic, uf Nn. In-. 1 :;, x 



granulation pretty tine, except on the front. Ratio of length to 

 breadth, 1:1.4 ; length of carapace 30 : breadth 4-j""" ; front 14""". 

 A', americanus (S&U8.)=J. areolatus Hath., figure M. differs very 

 little from some of the forms of this species. Although it averages 

 slightly narrower, there are specimens of //< /7/.s7// (No. 170 in 

 our collection, see table) as narrow as some of those from llra/.il, 

 referred to this species by .Miss Rathbun (in Coll. Yale Mils.). The 

 lateral marginal teeth are a little less oblique and less concave in 

 front, but in some specimens this distinction fails : indeed, the teeth 

 of opposite sides of one specimen may sometimes differ considerably 

 in outline, or about as much as the species differ in this particular. 

 But in this form the teeth are more thickened at base above, and are 

 rather more granulous at the edges. The fourth ami fifth teeth are 

 more squarrose, and the tips are turned upward. The third tooth 

 often differs but little from the others in size, but its tip bends for- 

 ward and the outer margin is convex ; it is not always as large as 



