SMITHSONIAN CONTRIBUTIONS TO ZOOLOGY • NUMBER 543 ...

68 SMITHSONIAN CONTRIBUTIONS TO ZOOLOGY
46. Third maxillipeds operculiform with distal and penultimate segments reduced
Chernocaris
Third maxillipeds conventional, distal segments not unusually reduced
*Conchodytes
47. Telson curving ventrad posteriorly, posterior margin without movable spines,
deeply incised and forming pair of fixed teeth separated by U-shaped sinus
Hamopontonia
Telson not curving ventrad, posterior margin bearing movable spines, not incised
48
48. Rostrum laterally compressed *Anchistus
Rostrum usually dorsoventrally compressed 49
49. Anterior margin of carapace nearly vertical, not produced anteriorly; 3rd pereopod
with dactyl simple, not biunguiculate Neoanchistus
(Madagascar, Oman; associated with bivalve mollusks)
Anterior margin of carapace produced moderately or strongly anteriorly as rounded
branchiostegal or pterygostomian lobe; 3rd pereopod biunguiculate, subdistal
tooth sometimes distalmost spine of series on flexor margin of dactyl
*Pontonia
50. Rostrum armed dorsally with 1 or more teeth 51
Rostrum dorsally unarmed, flattened 53
51. Rostrum with single subrectangular dorsal tooth at base Metapontonia
(Western Indian Ocean and Ryukyu Islands;
associated with fungiid corals)
Rostrum armed dorsally with 3-6 teeth 52
52. Carapace with several small suborbital spines; 3rd maxilliped with well-developed
exopod; 2nd pereopod with chela longer than carpus, movable finger small but
normal; telson with posterior spines straight Fennera
(Kenya, Seychelles, La Reunion, Maldives, Sri
Lanka, Great Barrier Reef of Australia, Hawaii,
Galapagos, and Pacific coast of America from
Mexico to Colombia; associated with stony corals)
Carapace with large postorbital spine; 3rd maxilliped with rudimentary exopod; 2nd
pereopod with chela shorter than carpus, movable finger semispherical; telson
with median and submedian posterior spines curved ventrad
Tectopontonia
(Tanzania; associated with coral Acropora)
53. Carapace without antennal spine; telson with dorsal spines slender . . . Platycaris
Carapace with prominent antennal spine; telson with dorsal spines robust
Platypontonia
54. Frontal margin formed by transverse or convex anterior margins of supraorbital
eaves; if transverse, margin armed with about dozen sharp teeth, median one
enlarged to form rostrum-like spike; if convex, margin unarmed, not bearing
rostral substitute 55
Frontal margin not formed by supraorbital eaves 56
55. Carapace having 2 large, blunt, compressed teeth in dorsal midline and postorbital
tubercle laterally, orbit open posteriorly Chacella
(Gulf of California; 30 meters,
associated with antipatharian)
Carapace without large middorsal prominences or postorbital tubercle, orbit closed
posteriorly Veleronia
(Ecuador and Galapagos Islands; 4-27 meters)
56. Carapace bearing immovable hepatic or postorbital tooth or spine 57
Carapace without hepatic or postorbital spine 64
57. Rostrum dentate in dorsal midline 58