136 U.S. NATIONAL MUSEUM BULLETIN 2 92 



In none of the three locahties was it found to be abundant. In the 

 highly polluted Mero River, where C. bocourti was most abundant (see 

 "Ecological Notes" for that species), no individuals of this species 

 were seen; however, near the mouth of the Salisbury River, a less 

 polluted stream, several individuals were collected or observed within 

 50 to 75 feet from the mouth. In the clear Layou River, a number of 

 individuals were seen near the mouth of the river, and a few were 

 collected. 



Its occurrence in the localities cited above and its absence in the 

 Mero River suggests that this species is less tolerant of high pollution 

 and muddy water than is C. bocourti. 



Distribution. — Nova Soctia to Uruguay (Bermudas, Bahamas, 

 Cuba, Jamaica, Puerto Rico, Saint Croix, Dominica), introduced 

 into coastal waters of Denmark, Netherlands, France, Italy, Greece, 

 Turkey, and Israel. 



Dominica Stations: 15, 30, 36 (sea level). 



Remarks. — The extreme variants of Callinectes sapidus in the 

 West Indies are so different from each other that they could easily 

 be interpreted as distinct species. In adequate series of specimens, 

 however, there seems to be no point of demarcation between the 

 typical form, which is prevalent along the east and south coasts of 

 the United States, and the sharp-spined tropical variety with rudi- 

 mentary submedian frontal teeth, which Rathbun called C. sapidus 

 acutidens. The two forms are apparently sympatric in the West 

 Indies, they intergrade almost completely, and the first pleopods of 

 adult males seem identical. 



The species identified as Callinectes acutidens by Boschi (1964, p. 

 45, pi. 2e-g, pi. 12) is almost certainly a different species, as indicated 

 by the presence of discrete, even if small, submedian frontal teeth 

 and by the straight first pleopods of presumably adult males. The 

 holotype of C. sapidus acutidens has long, sinuous first pleopods, 

 which agree very well with those of typical C. sapidus. Boschi's 

 species seems to be most closely related to the variable C. danae, but 

 it may represent an undescribed species. 



Family Pseudothelphusidae 



The classification used herein is based principally on that of Pretz- 

 mann (1965). After our manuscript was submitted for publication, 

 Bott (1968, pp. 47-49) proposed a different arrangement and demon- 

 strated that older names are available for some of Pretzmann's new 

 genera. Until the works of these two specialists are reconciled, the 

 classification of the Pseudothelphusidae will remain uncertain. 



