150 U.S. NATIONAL MUSEUM BULLETIN 292 



protuberance on outer surface near base of fingers. First pleopod of 

 adult male not armed distally witli scattered, short, stout spines; 

 terminating, in posterior view, in transverse, slightly sinuous distal mar- 

 gin, with broad, spine-tipped lobe on lateral margin and proximally 

 directed spinelike tooth mesially. A medium-sized species, maximum 

 carapace length in midline about 30 mm. 



Habitat. — In or near fresh water. 



Distribution. — Central and southwestern Mexico, Cuba, His- 

 paniola. 



Remarks. — Inasmuch as no "West Indian material of this species 

 was available to us, the figures were prepared from a syntype of 

 Pseudothelphusa dugesi, a Mexican species that is presumed to be a 

 synonym of P. americana. This synonymy needs verification by a care- 

 ful comparison of the male pleopods of West Indian and Mexican 

 specimens; the figures herein, especially figure 43e, should therefore 

 be used with caution. 



53. Pseudothelphusa (Pseudothelphusa) terrestris Rathbun 



Figure 43/ 



Pseudothelphusa terrestris Rathbun, 1893, p. 651, pi. 74: figs. 6, 7 [type-locality: 

 Atamajac, 3 miles west of Guadalajara, Estado de Jalisco, Mexico]; 1905, 

 p. 283. 



Potamocarcinus terrestris. — Ortmann, 1897, p. 318. 



Pseudothelphusa (Pseudothelphusa) terrestris. — Pretzmann, 1965, p. 4 [by 

 implication]. 



Diagnosis. — Carapace not very convex longitudinally or trans- 

 versely, about three-fifths as long as wide; cervical groove distinct, 

 concave anteriorly; anterolateral margin very obscurely denticulate, 

 with shallow emarginations near end of cervical groove and near 

 outer orbital angle; front not delimited dorsally by transverse crest. 

 Third maxilliped with merus narrowing distally, distolateral margin 

 convex; exopod reaching nearly to distal fourth of outer margin of 

 ischium. Pereiopods slender but not unusually long. Chela without 

 prominent, swollen protuberance on outer surface near base of fingers. 

 First pleopod of adult male not armed distally with scattered short, 

 stout spines; terminating, in posterior view, in oblique, concave distal 

 margin, with spine-tipped lobe on anterolateral margin and proximally 

 directed spinelike tooth mesially. A medium-sized species, maximum 

 carapace length in midline about 25 mm. 



Habitat. — In or near fresh water. 



Distribution. — West central Mexico; Cuba. 



Remarks. — The identity of Cuban specimens with this otherwise 

 Mexican species should be verified in the light of the importance 



