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Decapod Crustacea of Bermuda, Part II. 5 *' Q- e d 



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destitute of a scale. Uropods and telson thin and flexible distally, not 

 spinose. Legs with six functional segments. Larva a phyllosoma. 



Tribe Scyllaridca or Loricata. 



E. Carapace subcylindrical ; outer antennae elongated, with a long, tapered, 

 multi-articulated, and rather rigid spinose flagellum. Orbits not exca- 

 vated in the dorsal surface of the carapace. 



Family Palinurida:. 



EE. Carapace much depressed or flattened ; orbits excavated in its dorsal 

 surface; outer antennse short, flat, or squamiform, without a jointed 

 flagellum ; 5th pair of legs with small chelae in the female. 



Family Scyllaridce. 



DD. First three pairs of legs chelate, the first pair largest. Outer 

 antennas elongated, usually with a basal scale and a long flexible flagel- 

 lum. Uropods and telson rather rigid and usually spinose at the ends ; 

 outer lamella of uropods have a transverse suture. Legs have seven 

 segments. Branchiae numerous. 



Tribe Astacidea. 



F. Last thoracic segment consolidated with the preceding one. First 

 abdominal segment has a pleopod ; in the male developed as a genital 

 origan. Spermatheca external. Branchiae 19 pairs. Larva a zoea or 



Mysis-like (marine). 



Family Homarida. 



FF. Last thoracic segment movable. Spermatheca in the form of an 

 annulus. Branchiae 17 or 18 pairs. Larva not a zoea; similar to 

 adult in form (fresh-water forms). 



Family Astacidce. 



BB. Abdomen or pleon elongated, weak, with the segments not over- 

 lapping. Carapace small. Third pair of legs not chelate; ist and 2d 

 pairs chelate. 



Tribe Thallassinidea. 



AA. Body usually more or less compressed. Rostrum usually compressed 

 or slender; sometimes absent. Abdominal appendages (pleopods) 

 oar-shaped. Articulation between the carpus and propodus of the 

 chelipeds at only one fixed point. Branchiae various. 



Tribe Natantia (or Caridea, sense extended). 



REPTANTIA Boas=TRICHOBRANCHIATA. 

 SCYLLARIDEA Stebbing = LORICATA Heller (pars). 



Body convex, either depressed or subcylindrical, with a strongly 

 thickened shell. Antennules usually have two flagella. Antennae 

 may either have or lack a long flagellum ; antennal scale lacking ; 

 first joint of peduncle united to epistome. Gills trichobranchiate ; 



