REPORT ON THE CRUSTACEA MACRURA. 863 



first pair of antennae longer than the carapace, and in having the posterior portion of the 

 fifth somite carinated in the dorsal median line. 



The telson is long, tapering, dorsally grooved, laterally armed with three distant 

 spines, and terminates in two short median, and four kmg outer spines. 



In all the specimens taken the posterior two pairs of pereiopoda are reversed, that is, 

 they have the dactylos pointed anteriorly instead of posteriorly as it usually is. 



Pasiphasa, Savigny. 

 Pasiphxa, Savigny, Mem. sur les animaux sans vert., p. 50. 



Animal laterally compressed. Carapace short, not produced to a rostrum but 

 furnished with a large tooth on the dorsal crest. Mandible without a synaphipod. First 

 and second pairs of gnathopoda chelate, posterior three pairs feeble and imperfectly 

 developed and furnished with basecphyses. Pleon long. Ehipidura well developed 

 Telson short. 



Carapace less than one-third of the length of the body of the animal, laterally com- 

 pressed, and not so deep anteriorly as posteriorly. Frontal margin having the orbit 

 slightly excavate and imperfectly defined. The first antennal tooth represented as an 

 angle of the frontal margin projecting between the antennae ; the second antennal tooth 

 forms a well-defined tooth standing slightly within the frontal margin, and directed 

 obliquely forwards, thence the frontal margin recedes and meets the corresponding margin 

 of the lateral wall at a more or less obtuse angle. 



The pleon is laterally compressed, and the sides are deep ; the somites are longi- 

 tudinally subequal, the sixth being the longest. 



The telson is laterally compressed, dorsally flat, and tapers towards the extremity. 

 The ophthalmopoda are short, robust, and carry no ocellus. 



The first pair of antennas is biramose, and has the first joint of the peduncle ex- 

 cavate on the upper surface and furnished with a stylocerite. 



The second pair of antennas has a long flagellum and carries a scaphocerite that is 

 distally armed with a tooth. 



The mandibles are shell-shaped (conchiform), without molar process or synaphipod, 

 and consist of a serrate psalistoma. 



The first pair of siagnopoda is small and three-branched. 



The second pair of siagnopoda consists of a narrow ovate plate, projecting anteriorly 

 and posteriorly, and fringed with ciliated hairs that radiate towards the anterior distal 

 extremity ; on the inner side is a narrow cylindrical process tipped with a few hairs. 



The third pair of siagnopoda consists of a long, narrow, membranous plate, tapering 

 from the base to the distal extremity. The outer angle of the base is stouter, more 

 membranous, and is imperfectly articulated with the rest ; from the articulation the 



