130 THE ViiVAHE OF II. M.S. CHALLENGER. 



Length of the capitulum, 4*5 mm. 



Length of the peduncle 2 mm. Surface of the peduncle covered by chitinous and 

 rather prominenl scales. Seven of these scales form a longitudinal row, of which there 

 arc in all five : one of these rows is placed earinally, the two other pairs both laterally. 



Mouth of a very curious shape, chiefly in consequence of the great size of the second 

 maxillae (PI. X. fig. 11). Mandibles with three teeth, the first smooth, the second and 

 third serrated on I he superior edge. Inferior angles sharply pointed, bearing six stout 

 spines on the superior edge. The latter spines are placed very close to one another 

 (PI. XI. fig. 1). Maxillm not very robust, slender, bearing short and not very numerous 

 spines (in the free edge. Beneath the first four spines (two of which are larger) a dis- 

 tinct notch is visible ; the part beneath the notch is not protuberant, and bears short 

 hairs. Second maxilla very large, reaching far beyond the maxillae (PL XL fig. 2), fur- 

 nished with hairs on the anterior margin. 



Cirri slender and rather long. First pair with unequal rami, the shortest having 

 six, the longest eight segments, the latter only slightly thinner than the former. Last 

 cirrus with short segments bearing only two pairs of robust and one of very small spines 

 at the anterior margin. 



Caudal appendages elongate, very slender (PI. XL fig. 3), composed of twelve 

 segments, and furnished with a few hairs only. 



/'< n/'s well-developed, rather long, covered by minute hairs. Its length has not been 

 determined, as the organ was broken off in the specimen I opened to study its organisation. 



One of the specimens contained a small quantity — about twenty — of relatively large 

 eggs. Their length only slightly surpasses their breadth (0"42 mm. and 0"35 mm.). They 

 are all in the same stage of division, and there is no doubt that they are fecundated ova. 

 As no complemental male was present at the place it ordinarily occupies, and as, moreover, 

 this species was provided with a well-developed penis, I think it is very probable that 

 minute dissection will show this species to be hermaphrodite, as most other Cirripedia are. 



This species was taken at Station 192, September 26, 1874 ; lat. 5° 42' S., long. 132° 

 25' E.; noon; depth, 129 fathoms; bottom, mud. It was found attached to an arm of a 

 Comatula or Pentacnnus. 



Observations. — In the shortness of the carina this species much resembles Scalpellum 

 brevecarinatum. However it can lie easily distinguished from that species, especially 

 by the form of the carina! latus. 



Scalpellum triangulare, n. sp. (PL III. figs. 17, 18 ; PI. XL fig. 4). 



A alves thirteen ; surface of the valves covered by a rather thick chitinous membrane, 

 furnished with short woolly hairs. Carina simply bowed, with the umbo at the apex; 

 boat-shaped, without a flattened roof. Upper latus quadrangular, trapeziform. 



