452 



forming on each side a triangular lobe partly obtecting the basal joint of 

 the inferior antennae. The 3 anterior pairs of coxal plates rounded quadran- 

 gular in form, and having their distal edge minutely crenulated; 4th pair 

 considerably larger, about as deep as the corresponding segment, and produced 

 posteriorly, below the emargination, to an angular projection. Last pair of 

 epimeral plates of metasome forming a broadish expansion truncated at the 

 tip, and having the inferior corner slightly produced, the superior one 

 abruptly curved, its edge quite smooth. Eyes oblong reniform in shape, with 

 light red pigment. Antennae in female without any trace of calceolse; the 

 superior ones nearly half as long as the body, 1st joint of the peduncle 

 scarcely longer than the '2nd but somewhat thicker, last joint half the length 

 of the former, and produced at the end posteriorly to a rather small trian- 

 gular lappet, flagellum about twice the length of the peduncle, and composed 

 of numerous short articulations. Inferior antennae a little longer than the 

 superior, and having the last 2 joints of the peduncle about equal-size, and 

 the flagellum fully twice as long as the peduncle. Antennae in male much 

 more fully developed than in female, and having the opposite edges of the 

 last 2 joints of the peduncles bordered by a number of unusually large 

 calceolse, flagella very slender and elongated, without any calceolse. Anterior 

 gnathopoda with the propodos shorter than the carpus, and but very slightly 

 widening distally, palm somewhat oblique, though scarcely half as long as 

 the hind margin, from which it is defined by a very slight angle armed with 

 a transverse row of small spines. Posterior gnathopoda scarcely longer than 

 the anterior, and of a very similar structure, except that the propodos appears 

 somewhat more expanded in its outer part, being nearly oblong triangular 

 in form. Pereiopoda moderately slender, and edged with fascicles of small 

 spines, the 3 posterior pairs successively increasing in length, and having the 

 basal joint rounded oval in form, with the posterior edge perfectly smooth ; 

 that of last pair much the largest. Last pair of uropoda projecting somewhat 

 beyond the others, rami more than twice as long as the basal part, and 

 edged with small spinules and slender bristles. Telson reaching considerably 

 beyond the basal part of the last pair of uropoda, and oblong oval in form, 

 cleft extending beyond the middle, and slightly widening posteriorly, terminal 

 lobes obtusely pointed. Colour in the living state of the animal not yet 

 stated. Length of adult female reaching 12 mm.; that of male somewhat less. 

 Remarks. This form was first described by Kroyer as AmpliiflwV 

 inermi*, and subsequently referred by Sp. Bate to the genus Atijlns of Leach. 

 Boeck, however, adverting to its material difference from the species of that 

 genus, proposed to regard it as the type of a separate genus. The 



