Figube 142. — Osachila semilevis Rathbun. Animal in dor- 

 sal view, 3 mm. indicated. 



prismatic and lightly grooved. Abdomen narrow, 

 eroded along margins and on last two sejgments. 



Measurements. — Carapace of ovigerous female: 

 length, 13 mm. ; width, 15 mm. 



Habitat. — Thirteen to 50 fathoms. 



Type locality. — Gulf of Mexico, 25 fathoms. 



Known range. — Off Beaufort, N.C., to north- 

 west Florida. 



Remarks. — This southern species has been re- 

 corded north of Florida only twice, both times 

 from the Beaufort, N.C., area. Ovigerous females 

 have been taken from Florida in July. 



Subsection Brachygnatha 



Brachyura having buccal frame roughly quad- 

 rate. Last pair of legs normal in form, rarely re- 

 duced in size, and almost never dorsal. Gills few. 

 First abdominal appendages of female absent, fe- 

 male openings sternal. 



Superfamily Brachyrhyncha 



Fore part of body broad, rostrum reduced or 

 absent; body oval, round, or square, usually 

 broader than long. Orbits nearly always well en- 

 closed. 



Family Portunidae. The swimming crabs 



Crabs with body transversely oval, usually five 

 to nine lateral teeth. Last pair of legs usually dis- 



tinctly adapted for swimming, with terminal 

 article ovate, flattened. 



The family has a fossil record in America dat- 

 ing from the Cretaceous (Rathbun, 1935). 



Stephenson and Campbell (1960) discussed the 

 status of portunid subfamily names in the light of 

 recent action by the International Commission on 

 Zoological Nomenclature. This decision altered 

 the usage of Rathbun (1930a) in that the sub- 

 families Liocarcininae and Thalamitinae become 

 respectively Macropipinae and Portuninae. 



KEY TO GENERA AND SOME SPECIES IN THE 

 CAROLINAS 



a. Carapace with five teeth of about equal size on antero- 

 lateral margin; interocular teeth three (Subfamily 



Macropipinae) Ovalipes (p. 160). 



aa. Carapace with nine anterolateral teeth, lateral tooth 

 usually much larger than others ; interocular teeth 

 four, six, or eight ( Subfamily Portuninae). 

 b. Movable portion of antenna not excluded from orbit, 

 c. Palate with longitudinal ridge. 



d. Abdomen of male more or less triangular 



Port units (p. 162). 

 dd. Abdomen of male with last two segments 

 much narrower than basal segments 



CalUnectes (p. 168). 

 cc. Palate without logintudinal ridge 



Arcmicus cribrarius (p. 173). 



bb. Movable portion of antenna excluded from orbit by 



prolongation of basal article; anterolateral teeth 



alternately large and small Cronius ruber (p. 174). 



Subfamily Macropipinae 

 Genus Ovalipes Rathbun, 1898 



Rathbun, 1930a, p. 18. 



KEY TO SPECIES IN THE CAROLINAS 



a. Carapace yellowish gray, closely set With small annu- 

 lar spots of reddish purple ; iridescent spots between 

 each pair of anterolateral spines approximately alike 

 in size and shape ocellatus (p. 160.) 



aa. Carapace yellowish gray, without ocellated spots ; 

 iridescent spot between fourth and fifth anterolateral 

 spines large and nearly semicircular in shape 



guadulpen-sis (p. 161). 



Ovalipes ocellatus (Herbst) 



Figure 143 



Cancer ocellatus Herbst, 1799, p. 61, pi. 49, flg. 1. 

 Ovalipes ocellatus ocellatus: Hay and Shore, 1918, p. 426, 

 pi. 32, flg. 7. — Rathbun, 1930a, p. 19, pis. 2-3 (rev.). 

 Ovalipes ocellatus: Williams, 1962, pp. 39-41. 



Recognition characters. — Carapace about one- 

 fourth wider than long, convex, finely granulate 



160 



FISH AND WILDLIFE SERVICE 



