1894. PROCEEDINGS OF THE NATIONAL MUSEUM. 493 



edge that fits into a groove ou the iiiauus, and is without lateral teeth; 

 and no x)ectinations upon the mauus. 



liemarks. — This genus, as it was defined by Miers (1880), included all 

 those species in which the raptorial claw is without pectinations on the 

 penultimate joint and has the dactylus dilated at the base. From this 

 Brooks (188(J) has separated two groups of species. One, the genus 

 ProtosquiUa, includes forms having the dactylus unarmed and the tel- 

 son fused with the sixth abdominal segment; the other, the genus 

 Coronida,!^ composed of those species having the hind body depressed, 

 the dactylus armed with spines on the inner edge, and i)os.^essing very 

 small antennary scales and uropods. The forms that liave remained 

 up to this time in the genus Go no dactylus fall naturally into two groups, 

 one clustered around the well-known (}. chir<i[/ra, Latreille, and the 

 other around G. scyllarus, Linn;eus. These two groups are so distinct 

 that I am convinced that they should be given the rank of distinct 

 genera. The first group forms the genus Gonoduciyhis i)roper and cor- 

 responds exactly to Brooks's definition, while the other, for which I pro- 

 pose the name Odontodaetylus, would be excluded by his definition, and 

 will be described below. 



ANALYTICAL KEY TO THE SPECIES OF GONODACTYLUS. 



* Telson with 3 rounded lonjjjitudiual promineuces on the dorsal side. 



Whole dorsal surface of telson beset with fine prickles, only the submedlan 

 marginal spines well developed, the other 2 pairs obsolete; sixth abdomi- 

 nal somite with 6 smooth carina? SPixosfs, Bigelow. 



Like the above, but with only 4 distinct carinic on the sixth abdominal somite, 

 the whole dorsal surface of which is covered with prickles. 



SPixosissiMus, Ffeffer. 



Dorsal surface of telson without prickles; two pairs of marginal spines well 

 develoijed, only the lateral j)air obsolete CHiKA(iRA, Fabricius. 



* * Telson with more than 3 narrow carina? on the Dorsal side, and all 6 marginal 



spines developed. 



The 5 narrow cariuiB of the telson grouped together on a hemispherical promi- 

 nence Gi.AiiHors, lirooks. 



Seven closely packed dorsal carina^ on the telson graphukus, Miers. 



GONODACTYLUS SPINOSUS, Bigelow. 



Gotiodactylits spiiiosus, liiciELow, Johns Hopkins Univ. Circ, 106, j). 101, June, 

 1893. 



Diagnosis. — A (ronofZrtcfy/^.S' having cylindrical eyes, a transverse ros- 

 trum, with a long median spine and subacute anterolateral angles; 

 a smooth carai)ace, nearly oblong, the posterior margin being straight, 

 but the rounded anterolateral lobes projecting forward; the hind 

 body strongly convex; the lateral margins of the first exposed thoracic 

 segment not prodaced, of the next three segments rounded ; the first five 

 abdominal segments smooth above and with lateral marginal carina?, 

 the sixth segment with six broad and smooth dorsal carina?, each end- 

 ing in a spine; three high, rounded, longitudinal dorsal prominences on 



