REPORT ON THE CIRRIPED1A. 1 :J7 



the two valves are united together is three. The basal margins of these valves are also 

 very irregular. The occludenl margin of both valves is furnished with a distinct bul 

 narrow ridge. 



Basis. — I have not distinctly observed the basal membrane. The interspace Left 



open between the basal edges of the parietes is narrow, and has a very irregular shape. 

 Body of the animal. — The body is much flattened; yet il does nut lie parallel t>> the 



surface of attachment, as, according to Darwin, is the case in the other species of the genus. 

 The mouth is flattened, it is not bullate, and it stands at a distance from the adductor 

 scutorum muscle. The labrum (PL XL fig. 5) has its crest surmounted by a row of very 

 numerous aud small teeth ; the palpi are of moderate size, but the tips are very distant 

 from each other. They are not curved, but they bear, as in the species described by 

 Darwin, the bristles only on their outer sides and extremities. The rounded swelling 

 on each side of the labrum to which they are attached is present, as Darwin has indicated. 

 The mandibles in this genus, according to Darwin, have three upper main teeth, with 

 two or three minute lower teeth, or (in P rruca nexa) with the lower part pectinated 

 with small spines. The present species has the mandibles as in the latter species (PI. XI. 

 figs. 6 and 6*). The only point to be added is, that in the specimen I have investigated 

 the mandible of the one side was furnished with three, that of the other with four, teeth; 

 an asymmetry to which we must not attach too great importance. The maxillce (PI. XI. 

 fig. 7) have a very deep notch behind the two upper larger spines; the lower part is 

 rather narrow, and bears some spines, which are not very strong. This lower part forms 

 a step-like projection. The outer maxilla' (PI. XI. fig. 8) are slightly prominent, and 

 not deeply lobed on their inner surfaces. They are clothed with bristles. 



Cirri (PL XI. fig. 9). — The first pair is relatively stout, and the pedicels especially 

 are well developed. The two rami are equal in length and thickness, and both have 

 thirteen segments. These segments are thickly clothed with spines. The second paw 

 has the posterior ramus much longer than the anterior; it is almost twice as long; the 

 number of segments of the short ramus is eight ; that of the long ramus thirteen. The 

 two rami of the third pair show only a very slight difference in length. The fourth to 

 the sixth pairs have numerous elongated segments, bearing as a rule three pairs of long 

 slender spines in front and two or three slender spines on the dorsal edge of each segment. 



Caudal appendages long and slender, and having eleven segments in the speci- 

 men I investigated. The "penis is long and slightly swollen at the extremity. 



This species was found attached to the strongly corroded surface of a part of a shell, 

 the nature of which I was unable to ascertain. 



The specimen of this species which I dissected contained eggs. These were in a very 

 early stage ; their shape was not very elongate, their Longesl and shortest dimensions 

 being respectively 0'415 and - :32 mm. The average size of the specimens was 8 mm. 

 in height and <J mm. distance from the apex of the rostrum to that of the carina. 



(ZOOL. CHALL. EXP. — rART XXV. — 1883.) Bb 18 



