STALK-EYED CRUSTACEA 331 



d}. Antennal peduncles composed of five segments, 

 the second segment furnished with a projecting spine. — 

 {Paguridca.) 



e. Abdomen symmetrical, of seven segments, terminat- 

 ing in a swimming organ. 



e^. Antennal peduncle composed of four segments. — 

 {Galatheidea.) 



Group I. Dromidea. 



Dromidea . . Dana, Miers, Haswell Henderson. 

 Dromiacea . . De Haan. 



Carapace subglobose or subquadrate, the frontal 

 region narrow. The last pair of legs, sometimes the 

 penultimate pair, subdorsal in position and of small 

 size. Abdomen folded under the thorax, the penultfmate 

 segment usually without appendages ; five pairs of 

 appendages in the female, the first pair rudimentary. 

 Lateral thoracic apodema united in a common centre, 

 forming a sternal canal. External maxillipedes with 

 the third and fourth joint subquadrangular. 



Family I. Dromidae. 

 Family II. Homolidae. 



Synopsis of the Families. 



A. Carapace subglobular or flattened. 



a. Fourth and fifth pair of legs sub- 

 dorsal, usually prehensile. 



a^. Eyes retractile, with well-defined 

 orbits. 



a-. Antennules folded into special fossae. 

 — {DroiiiidcE.) 



