33 



on the front side and one or two very short spines on the posterior margin near the extremity. 

 The latter margin in some of the segments bears a spine at about the middle of its length ; 

 this margin, moreover, is delicately hirsnte with extremely short hairs or teeth. 



Caudal appendages long, consisting of 8 narrow segments. Each segment bears one 

 longer hair near the extremity; those on the six last segments are very long, very stout and 

 distinctly serrated. On the interior margin each segment has one or two much more delicate hairs. 

 The last segment bearr a group of three very long, feathered hairs or spines at the extremity. 



No p e n i s. 



Male. I found only one male on the specimen I investigated more closely in this regard : 

 it was the specimen with partly calcified valves represented on PI. VII in Fig. 11. I found it on 

 the inner side of the left scutum, near the occludent margin. It was not in a very good state 

 of conservation, the body with the cirri hanging out of the opening of the sac. The longest 

 diameter of the sac was about 1,2 mm., the breadth slightly over 0,5 mm. The sac or mantle 

 itself was very thin and soft, not resistant, tough. About the middle of the longest diameter 

 little prehensile antennae are attached. The surface shows numerous very short hairs, arranged 

 in transverse rows, placed at short distances from one another. 



This species was taken at the following places : 



Stat. 45. April 6, 1899. Lat. 7 24 S., Long. ii8°is'.2E. Depth 794 m. Bottom : fine grey 

 mud. One almost perfectly, two imperfectly calcified specimens. 



Stat. 256. December 11, 1899. Lat. 5°2Ó'.6S., Long. I32°32'.5E. Depth 397 m. Bottom: 

 greyish green mud. One perfectly calcified specimen. 



Affinities. This very interesting species is perhaps more closely allied to Sc. rutilum 

 Darwin than the descriptions of the two species would at present lead us to suppose. It is also 

 similar in several regards to Sc. distiuctum Hoek. 



13. Scalpellum distiuctum Hoek. PI. VII, hg. 12. 



HOEK, Cirripedia collected by H. M. S. "Challenger". 1883. p. [II, pi. VI, fig. 10 & 11. 



H. M. S. "Siboga" collected a Scalpellum at three different Stations which I think is 

 identical with the above-named species. The very curious forms of the scutum, the upper latus 

 and the infra-median latus leave no doubt on the matter. 



Yet the resemblance is not absolute and I have therefore thought it useful to give a 

 figure of one of the "Siboga" specimens. The original description was given from a single 

 specimen, a circumstance which of course makes that description less reliable. 



The smallest of the two specimens collected by the "Siboga" (total length 20 mm., length 

 of the capitulum 14,4 mm.) has been figured. (The capitulum of the "Challenger" specimen 

 had a length of 15,5 mm. and that of the largest "Siboga" specimen 19 mm.). Comparing the 

 figure with that given in my "Challenger" Report (PI. VI, fig. 10) one is struck with the much 

 more prominent lines of growth and ridges on the valves of the "Challenger" specimen. To 

 some extent this is the fault of the lithograph: on the original pencil-drawing these lines are 

 much more delicate-, on the upper part of the infra-median latus they are however stronger 

 developed in the "Challenger" than in one of the "Siboga" specimens. 



83 



