86 IOWA STUDIES IN NATURAL HISTORY 



MiCROPHRYs iNTERRUPTus Rathbun 

 Plate II, fig. 5. 



Proc. Biol. Soc. Washington, vol. XXXIII, 1920, p. 24. 



Fort Barclay, English Harbour, Antigua, July 9; 1 6 1 9 

 juv. 



Needham Point, Barbados ; May 18 ; 1 5 . 



Known previously only from Cuba, the type locality. 



Measurements. — The male from Needham Point is only slightly 

 larger than the type male; the male from Fort Barclay is con- 

 siderably larger, total length of carapace 16.7, length of horns 

 2.4, width of carapace without spines 13.6, with spines 13.3 mm. 

 The carapace is widest above the bases of the first ambulatory 

 legs where it exceeds slightly the width between the tips of the 

 posterolateral spines, which are above the bases of the second 

 ambulatory legs. The egg-bearing female is about the same size 

 as the male and is concealed beneath a mass of algae and other 

 small organisms. 



Relationships. — M. hicornutus is very widespread and abun- 

 dant, and a very variable species, but the form which I call inter- 

 ruptus appears to be consistently different. It differs from bi- 

 cornutus in being wider in proportion to its length, and wider 

 across the orbits in proportion to its posterior width; in the 

 greater prominence of the oblique branchial protuberances which 

 are in line with the postero-lateral spine ; in the more transverse 

 direction of the arch of four tubercles on the intestinal region; 

 in the shorter and more transverse tooth at the antero-extemal 

 angle of the basal antennal segment, which is very little ad- 

 vanced in dorsal view beyond the preorbital angle, and in ventral 

 view gives the segment much greater relative width than in 

 hicornutus ; in the presence of a small but well-developed tooth 

 or lobe on the infra-orbital margin, just outside the antenna! 

 segment ; this tooth is lacking in hicornutus. 



Stenocionops furcata (Olivier) 



The Horned Crah, Nat. Hist. Barbados, 1750, p. 266, pi. XXV, 



fig. 3. 

 Stenocionops furcata Rathbun, Bull. U. S. F. C, vol. XX for 



1900, part 2, 1901, p. 73. 



