REPORT ON THE CRUSTACEA MACRURA. 295 



with two small teeth, with indications of a third at the extremity, and with two larger 

 teeth posterior to the gastric region ; a short tooth on the anterior margin of the carapace, 

 corresponding with the external orbital angle, and one posterior on the hepatic region. 



The dorsal carina on the first somite of the pleon is produced into an anteriorly directed 

 tooth, and on the sixth into a posteriorly directed one. 



Telson tapering, dorsally depressed, and nearly equalling the lateral rami of the 

 rhipidura in length. 



Habitat. — St. Thomas, West Indies, in shallow water. One specimen ; male. 



Off Bahia, 20 fathoms. One specimen ; female. 



Our specimens differ in some details from Milne-Edwards' description and figure, 

 but not sufficiently to mark it as specifically distinct. 



Milne-Edwards' figure has the ophthalmopod long and cylindrical, but this may be, 

 and probably is, only an artistic misrepresentation, and the flagella of the first pair of 

 antennse are represented as being very short, and the peduncle of the second pair of antennae 

 reaches nearly to the extremity of the scaphocerite, and the terminal flagellum is flattened 

 and strongly ciliated on both borders. 



The rostrum in our specimen is smooth below and directed obhquely upwards and 

 forwards ; it has on the dorsal surface two small teeth ; an anterior apical one, only 

 determinable with a lens, and a posterior one directly over the orbital margin, 

 whereas Milne-Edwards says there are two small teeth and both near the j)oint, 

 although he figures a third as a rudimentary one on the under side of the apex. Behind 

 these, on the dorsal surface, are two others in the median line, corresponding with 

 Milne-Edwards' description, as also does the general plan, but the appendages of the 

 animal require further description in detail. 



In the Challenger specimen from the West Indies, there is no tooth on the lower sur- 

 face. In that from the coast of South America there is one on the lower margin. 



The ophthalmopod is very short and biarticulate, a small appendage being attached 

 to the first joint ; the ophthalmus, forming the larger portion, is broad, reniform, flattened 

 on the inner side and rounded on the outer, and reaches anteriorly beyond the extremity 

 of the rostrum. 



The first pair of antennas (fig. 3, b) has the first joint longer than the eye, deeply 

 excavated and thickly fringed with hairs on the upper surface to receive and protect the 

 eye when at rest ; the inner margin is straight and in contact with its fellow throughout 

 its entire length ; the prosartema is rudimentary and the stylocerite is almost as long as 

 the joint, and is separated nearly to the base, while another sharp tooth at the outer angle 

 projects forwards to nearly half the length of the second joint, which is short and 

 cylindrical, as also is the third, which carries at its extremity, in the male specimen, two 

 slender flagella that are about half the length of the peduncle. 



