Genus Sicyonia Milne Edwards, 1830 by Burkenroad (1945) and Hall (1956). The 



„ , . ia „. „„ , Qjr „ . „„„ iaKfl „ a7 name Sicyonia H. Milne Edwards, 1830, has been 



Burkenroad, 1934a, p. iO. — 1945, p. 1. — Hall, 19a6, p. 87. — J 



Hemming, 1958b, p. 126. validated under Plenary Powers of the Inter- 



The generic name Sicyonia has had a complex national Commission on Zoological Nomenclature 

 nomenclatural history, and was reviewed in detail (Opinion 382; Hemming, 1958b). 



KEY TO SPECIES IN THE CAROLINAS 



(Modified after Lunz, 1945) 

 a. Antennal angle not armed with a definite spine; ischium of first leg armed with a spine. 



b. Rostrum (excluding tip) with two dorsal teeth before posterior margin of orbit; carina of carapace with three teeth , 



first tooth smallest ..laevigata (p. 33) . 



bb. Rostrum (excluding tip) with three dorsal teeth; carina of carapace with three evenly spaced, subequa 1 



teeth ..parri (p. 34). 



aa. Antennal angle armed with definite spine (sometimes blunt); ischium of first leg unarmed. 



b. Three or four teeth on carina of carapace behind orbital margin, three large; carina high; rostrum extending beyond 



midpoint of cornea, with two dorsal teeth (excluding tip) - -brevirostris (p. 35). 



bb. Two or three teeth on carina of carapace behind orbital margin, two large and behind hepatic spine; rostrum not 



extending beyond midpoint of cornea, with one or two dorsal teeth (excluding tip) .... ..typica (p. 36). 



bbb. Two teeth on carina of carapace behind orbital margin, one behind hepatic spine; rostrum with three dorsal 

 teeth (excluding tip), 

 c. Fourth abdominal segment with anterior and posterior ends of ventral margin of pleura spined or 



angular,.-. ..dorsalis (p. 37). 



cc. Fourth abdominal segment with posterior end of ventral margin of pleura rounded stimpsoni (p. 38). 



Sicyonia laevigata Stimpson 



Figures 22-23 



Sici/onia laevigata Stimpson, 1871b, p. 131. — Hay and Shore, 

 1918, p. 379, pi. 25, fig. 1. 



Euaicyonia laevigata: Burkenroad, 1934a, p. 76, figs. 21. 26, 

 32 (rev.).— Lunz, 1945, p. 4, fig. 1. 



Recognition characters. — Integument rather 

 firm, finely granulate and more or less sculptured. 

 Rostrum elevated at angle of about 20 degrees, 

 about, half as long as carapace; armed dorsally 

 with two teeth not counting tip ; terminal portion 

 divided into four teeth; notch between median 

 pair shallower than dorsal and ventral notches; 

 often two short, stout, asymmetrically placed, 

 mobile spines distally above ventral margin. 

 Postrostral carina with three teeth behind orbital 

 margin; anterior one slightly advanced beyond 

 level of hepatic spine and about same size as 

 rostral teeth, often appearing as part of rostral 

 series; posterior two teeth closer together; carina 

 sometimes nearly obliterated anterior to each 

 tooth. Antennal angle unarmed but not rounded. 

 Ocular stylets short. 



Abdominal segments marked by tergal carinae 

 deeply notched behind on first to fifth segments. 

 First abdominal segment with carina produced 

 into an elevated anterior tooth; marked laterally 

 by two grooves, a long posteromedian and short 

 anteromedian groove obliterated a short distance 



Figure 22. — Sioyonia laevigata Stimpson. A, carapace 

 and first two abdominal segments in lateral view, ap- 

 proximately X 3 ; B. petasma of male In ventral view, 

 approximately X 20.5 (A-B after Burkenroad, 1934a 1. 



ventral to juncture with anterior margin of 

 pleura but with short resumption below juncture. 

 Second and third segments with anterior and 

 short posterior tergal grooves; a short, shallow 

 anteromedian pleural and a posteromedian pleural 

 groove turning sharply anteriad somewhat above 

 middle of lateral surface. Second segment with 

 carina narrowly and deeply cleft above juncture 

 of tergal groove. Fourth and fifth segments with 

 posterior tergal groove, and an anterior groove, ob- 

 literated forinterval belowshort dorsal section;re- 

 appearing farther ventrad. Sixth segment with a 

 posteromedian pleural, anterior tergal and a longi- 

 tudinal groove; carina ending in a strong posterior 

 tooth. Ventral pleural margins rounded except 

 for a posterior tooth on fifth and sixth segments. 



MARINE DECAPOD CRUSTACEANS OF THE CAROLINAS 



33 



