158 Bulletin, Vanderhilt Marine Museum, Vol. HI 



Technical description : Female : Rostrum six mm. long, carapace 

 12.5 mm. long, abdomen 31 mm. long. Rostrum blade-like, directed 

 foinvard at an acute angle, the apex a broad, acute triangulate tooth ; 

 the inferior margin armed on its distal half with two small, acute, tri- 

 angulate teeth ; the upper rostral margin is armed with two teeth ; 

 the anterior of which is placed about one-third the distance from the 

 apex, while the second spine is one-third of the distance from the base. 

 There is a crested carina behind the rostrum, extending the length of 

 the carapace and ornamented with four, acute, triangulate, forward- 

 and upward-directed spines, spaced subequally on the anterior four- 

 fifths of the carapace. The spines decrease slightly in size from front 

 to rear of the series, but the smallest one is substantially larger than 

 the rostral spines. 



The preorbital spine is forward-directed, very acute, about half as 

 long as the eyestalk; the suborbital angle is triangular and not spin- 

 ous ; the antennal spine is also acute, forward and slightly outwardly 

 directed; there is no branchiostegal spine, but the pterygostomian 

 spine is subequal to the antennal spine but is directed straight for- 

 ward. The lateral margin of the carapace is convex and is emphasized 

 by a flat carina. The posterior margin also has this carina. The pos- 

 terior margin is concave in the median area and convex on either side. 

 There is a slight longitudinal depression on either side anteriorly be- 

 low the antennal spine. The entire surface is marked by fine punctae 

 from which fine, slender, upstanding hairs arise. 



The first abdominal segment is not quite as long in the median line 

 as the second and has its lateral part no wider than the median, but 

 rounded, and with two spines separated by a shallow concavity on the 

 distal, lateral margin and with a depression on the outer face. The 

 second segment is widened laterally into a subcircular plate that over- 

 laps the first and third segments and has at its apex a single spine ; 

 two depressions on its outer face. The third segment is much length- 

 ened in the median region, being twice as long as the second segment, 

 with the posterior margin convex in the median line, then slightly con- 

 cave and again convex on the lateral margin, which is about as narrow 

 as that of the first segment and is produced to an acute median spine 

 on the lateral margin; the fourth segment is only one-third as long 

 as the preceding segment in the median line and has its median pos- 

 terior margin nearly straight at each end, with a small, rounded tooth 

 separated on each side by a shallow sinus, beyond which the lateral 

 portion is very convex on the posterior side and moderately so on the 



