152 
BULLETIN OF THE UNITED STATES FISH COMMISSION. 
Gonodactylus oerstedii Hansen. (Figs. 1 and 2.) 
Qonodactylus chiragra, Smith, S. I., Brazilian Crustacea, Trans. Conn. Acad., ii, p. 41, 1869. Miine-Edwards, A., Nouv. Arch. 
Mus. Hist. Nat., vol. iv, p. 65, 1868. Martens, E. v., Cubanische Crust. Arch. f. Naturg. Jahrg. 33, Bd. n, p. 147, 1872. 
Brooks, Voyage of H. M. S. Challenger , xvi, n, p. 56, 1886. Brooks, Mem. Nat. Acad. Sci. v, p. 353, pis. x and in, 1892. 
Bigelow, Stomatopoda collected by the steamer Albatross, Proc. U. S. Nat. Mus., vol. xvn, p. 495, 1894. 
Gonodactylus oerstedii, Hansen, H. J., Isopoden, Cumaceen, und Stomatopoden, Ergebnisse der Plankton-Expedition der 
Humboldt-Stiftung, Bd. n, G. c., footnote p. 65, 1895. Rankin, Crustacea from the Bahamas, Ann. N. Y. Acad. 
Sci., xi, p. 253, 1898. Borradaile, Crustaceans from the South Pacific, Proc. Zool. Soc. Lond., 1898, p. 35, pi. v, fig. 3. 
Diagnosis . — A Gonodactylus having cylindrical eyes; the rostrum transverse, with an acute median 
spine as long as half the width of the rostrum and elevated somewhat above the rounded lateral 
angles; a smooth carapace, nearly oblong, the posterior margin being very slightly concave and the 
rounded anterior lateral angles projecting forward; hind-body strongly convex; the lateral margins of 
the first exposed thoracic segment not produced, the margins of the next three segments rounded; the 
first five abdominal segments smooth above, with marginal carinse and rounded posterior lateral 
angles; sixth abdominal segment with 6 longitudinal dorsal carinse, the submedian and intermediate 
pair being well rounded prominences more or less elliptical in outline and often possessing a minute 
posterior spine, which may, however, be obsolete or absent, the lateral pair narrow, ending in the 
Fig. 1. Telson and adjacent parts of Gonodactylus oerstedii. Female, x 5; sc, supplementary Carina; 
im, intermediate spine; in, mobile tip of submedian spine; bp, basal prolongation of europod. 
strong posterior lateral angles, and with a transverse carina extending between the ends of the lateral 
carinse and, when the abdomen is fully extended, hidden under the posterior margin of the fifth 
segment; 3 high rounded longitudinal dorsal prominences on the telson, submedian spines large, with 
minute mobile tips and finely serrated on the inner edge, intermediate spines prominent, and lateral 
pair obsolete; 6 marginal carinse, each intermediate one having on its inner side a shorter supple- 
mentary carina; the surface of these sculpturings being smooth and polished, except that the supple- 
mentary carinse are sometimes slightly serrated and the intermediate central prominences sometimes 
show faint indications of a posterior spine; and the basal prolongations of the uropod ending in 2 
flattened curved spines, of which the outer one is the longer. 
General description . — This form is so very similar to G. chiragra Fabr. that most authors have 
identified it with that species. S. I. Smith (’69) stated that he found a slight difference between the 
American species and the true G. chiragra, but Hansen (’95) is the first to describe this as a distinct 
species and to point out the character by which it can be recognized. This distinguishing character- 
istic is the small supplementary carina (sc, fig. 1 ) on the inner side of each intermediate marginal 
