66 CRUSTACEA MALACOSTRACA. IV. 



59. Makrocylindrus spiniventris n. sp. 

 (PI. IV, tigs. 6 a— 6 d). 



Immature Female. Seen from the side the carapace, not including the considerably produced 

 pseudorostrum, is a little oblong-ovate; seen from above it is rather oblong-oval. The ocular lobe without 

 visual organs, in one specimen with a single large spine, in another (fig. 6a) with a pair of similar large spines 

 directed upwards and much forwards. Behind the ocular lobe the carapace has a transverse, sattle-shaped 

 depression very conspicuous especially from the side (fig. 6 b) ; just behind the ocular lobe there is a smaller, 

 and close behind this a large and thick, procurved spine. The upper margin of pseudorostrum is anteriorly 

 curved much downwards, so that the end is rather obtuse, and a little behind this end a pair of dorsal, large, 

 procurved spines, and close behind these two minute denticles, are found. Pseudorostrum has besides on the 

 side below the ocular lobe two or three large and thick spines, and below the sattled-shaped depression and 

 somewhat more backwards the lateral surface has a good number of somewhat small to minute denticles 

 irregularly dispersed; behind the base of the antennae the lower margin has 4 long and robust teeth, and 

 behind them a few minute teeth. — The free thoracic segments smooth ; third and fourth segments completely 

 fused without any suture between them above and half downwards the sides (fig. 6 c) . The abdominal segments 

 increase in length from the second to the fifth, which is about as long as the sixth. First segment has below 

 in the median line 3 very long, spiniform teeth rather near each other at their base but diverging strongly, 

 and somewhat behind them a rather small tooth directed much backwards (in the figure indicated as seen 

 through the leg) ; the same segment has, besides, between the upper surface and the side 2 or 3 spines, the 

 posterior one strong. Second segment with a pair of robust sublateral denticles ; the following segments show 

 individual variation, as in one specimen they have no denticle, while in another specimen of the same size 

 third and fourth segments have a similar pair of sublateral denticles, and fifth segment 3 pairs of sublateral 

 denticles, the posterior pair robust. 



Antennulae (fig. 6 b) long; in the peduncle first joint has a long, spiniform process below at the end; 

 second joint, which reaches beyond pseudorostrum, is a little less than twice as long as first joint and more 

 than twice as long as the third; the upper flagellum scarcely as long as second peduncular joint, 4-jointed, 

 with the 3 proximal joints subequal; lower flagellum somewhat longer than first joint of the upper, 3-jointed, 

 but first and third joint very short. First pair of legs broken at the end of second joint, which is very robust 

 with several strong teeth on the lower side. The three posterior pairs of legs have a single tooth or a couple 

 of teeth on the proximal part of the anterior or posterior margin of second joint ; merus of third and fourth 

 pairs of legs somewhat elongated, but not fully half as long again as the three distal joints together, and 

 these pairs each with a tiny rudiment of an exopod terminating in a seta ; this rudiment is so small that on 

 fig. 6 c it was necessary to render it proportionately too large. - - Uropods (fig. 6 d) somewhat short and 

 slender, the peduncle reaches about to the anal doors of the telson and has 5 — 7 spines on its inner margin; 

 first joint of the endopod scarcely two-fifths as long as the peduncle, with 7 spines on the distal half of its 

 margin; second joint somewhat short with 3 marginal spines (third joint mutilated in my specimens); the 

 exopod slightly longer than the two proximal joints together of the endopod. Telson (fig. 6 d, and t) very long, 



