164 



Gen. 1. Ampelisca, Kroyer, 1842. 

 Syn: Araneops, Costa. 

 Pseudophthalinus, Sthnpson. 

 Tetromatus, Sp. Bate. 



Body moderately slender and highly compressed, with smooth and 

 shining surface. Cephalon with the frontal part more or less produced, post- 

 antennal corners obsolete. Anterior pairs of coxal plates rather deep and 

 arranged in such a manner, that the posterior edge of each overlaps the an- 

 terior edge of the succeeding one; 1st pair scarcely deeper than the others, 

 but more or less expanded distally, and generally (but not always) quite 

 concealing the basal part of the inferior antennae, as also the oral parts ; 

 4th pair obliquely truncated below the posterior angle. Eyes, when present, 

 2 on either side, each generally exhibiting a well-marked circular corneal 

 lens. Antennae very slender, their mutual length different in the different 

 species. Mandibles with the body very short, palp of moderate length, and 

 having the 2nd joint laminarly dilated, the last very narrow and linear. First 

 pair of maxillae with the masticatory lobe transversely truncated and armed 

 with strong spines, basal lobe comparatively small, and without distinct 

 marginal setae, palp well-developed, with the terminal joint gradually expanded 

 distally, and armed at the tip with several strong teeth. Second pair of 

 maxillae with the outer lobe larger than the inner, both densely setous at the 

 tip. Maxillipeds with the basal lobe oval, obliquely rounded at the tip, 

 masticatory lobe oblong, and reaching about to the end of the antepenultimate 

 joint of the palp, penultimate joint of the latter nearly club-shaped and 

 scarcely half as long as the antepenultimate one. Anterior gnathopoda, as a 

 rule, shorter and stouter than the posterior ones, with the propodos more or 

 less dilated in the middle, that of the posterior pair generally very narrow 

 and attenuated distally. The 2 anterior pairs of pereiopoda with the carpal 

 joint extremely short, dactylus long and narrow. The 2 succeeding pairs with 

 the basal joint very broad, its anterior edge strongly curved in the middle, 

 carpal joint, with a single series of small denticles on the outer side, somewhat 

 within the posterior edge. Last pair of pereiopoda with the basal joint 

 obliquely expanded, posterior lobe short and broad, with a dense series of 

 ciliated setae on the terminal edge; proposal joint more or less foliaceous, 

 dactylus lanceolate. Last pair of uropoda rather large, reaching considerably 

 beyond the preceding pairs, rami more or less foliaceous, the inner broader 

 than the outer. Telson oblong and cleft nearly to the base, the incision very 

 narrow, fissure-like. 



Remark*. The present genus was established by Kroyer as early 

 as 1842, and the name, proposed by that author, has therefore evidently the 



