115 



Before eoine to describe this rare animal, I niav call attention to the fact that the 

 figures on Plate XXIY of the Report on the Challenger Macrura are wrongly numbered, 

 because, e. g., Figure i that represents an individual looked at from the ventral side, cannot 

 belong to Xcphropsis rosea^ for in this species the abdominal pleura carry no sharp tooth on 

 their anterior margin. The inner antenna, represented Fig. b, differs so much from that ot 

 Fig. I on Plate XXIII, the joints of the longer flagellum being more elongate and much less 

 numerous, that these two figures also cannot belong to one and the same species. Figure i 

 seems to represent, not Xcphropsis rosea, but Xephropsis Sickini^ Figure d remains uncertain, 

 because in the specimen which is lying before me, these flagella are composed of a much 

 larger number of joints. 



The specimen, collected by the "Siboga" expedition, is 42,8 mm. long, a little longer 

 than that which was described by Spence B.a.te and which was 38 mm. long; according to 

 Alcock, however, Xcp/iropsis Sii/niii becomes twice as large, viz. 84 mm. The rostriun is 

 9,4 mm. long, the carapace 12,4 mm., the abdomen 21 mm.; the rostrum that measures three- 

 fourths the length of the carapace, conform to Alcock's description, appears somewhat shorter 

 than in the "Challenger" type. I must, however, remark that Fig. 3 of Plate XXIII does not 

 agree with the description; the rostrum, indeed, is described as being "more than half the 

 length of the carapace", but in the figure both seem to be equally long. The rostrum is at 

 first somewhat declivous, its distal third slightly turned upward ; it is slender, the e.xtremity 

 acuminate. The rostrum is armed on each side with two .slender spines, the anterior pair 

 immediately behind the middle, the posterior midway between the anterior and the base; the 

 two posterior spines are a little shorter than the anterior ones. The lower edge of the rostrum 

 is smooth and unarmed ; its lateral margins that are for the rest unarmed, are fringed with 

 ciliated hairs and the distal half of the rostrum, beyond the anterior pair of spines, carries on 

 each side of the median ridge some longer plain hairs. The pro.ximal half of the rostrum 

 shows between the lateral spines two rows of small, acute granules, each granule tipped with 

 a fine hair; the two ridges diverge at the base of the rostrum and, enclo.sing between them a 

 small, rounded tubercle in the mid-dorsal line of the gastric region, at the level of the hepatic 

 grooves, converge towards the cervical suture, forming thus immediately before it a narrow 

 furrow. At the base of the rostrum one observes at either side a .strong spine, as long as the 

 anterior spine of the lateral margin, but somewhat thicker at its base, and immediately behind 

 them the described divergent ridges on the gastric region arc armed with sharp spinules that 

 gradually diminish in length and size backwards; the foremost pair of these sjjinules are half 

 as long as the posterior lateral spines of the rostrum. The post-antcnnal s[)ines that are directed 

 forward, outward ami ujiward, are somewhat longer than those at the base and on the lateral 

 margins of the rostrum; these 4 pairs of spines are all directed forward. 



iMgiu-e 3 on Plate XXIII of the Challenger Report, that represents certainly the same 

 species as that which I am describing, appears also ine.xact, as regards the position of the 

 cervical groove. In this figure, indeed, that part of the cephalothorax which is situated before 

 the cervical groove, appears much smaller than the posterior part, but in the specimen lying 

 before me, just the contrary is observed, the anterior part being considerably larger than the 



