igog.] N. Annandai^e : The Indian Cirripedia Pedunculata. 113 



of the sixth cirri, slender, slightly spatulate, rounded at the tip, which bears a pencil 

 of stout hairs, some of which are considerably longer than the appendage itself : the 

 . upper third of the posterior edge bearing similar hairs. Penis slender, abruptly 

 pointed at the tip, moderately long, clothed with closely set rings of minute spines 

 and bearing a few scattered hairs. 



Mouth PA^rs.—Labrum broad, bearing a row of short, rather stout teeth. 

 Palpi short, slender, bearing a pencil of long hairs at the tip. Outer maxillœ broadly 

 oval, densely fringed. Maxillœ with a broad, rather shallow, pointed incisure near the 

 outer edge, which is armed with a long, slender spine ; between this and the incisure 

 two or three more slender spines of varying length ; a long slender spine immediately 

 on the other side of the incisure followed by several others (usually six) of varying 

 lengths ; the inner edge of the appendage irregularly serrated and bearing a fringe 

 of fine hairs. Mandibles bearing five teeth, the outermost of which is by far the 

 largest and is separated widely from the rest ; the fourth tooth short and often blunt, 

 the fifth slender and rather long ; the four inner teeth and the part of the appendage 

 adjacent to them clothed with minute spines; the inner edge of the appendage bear- 

 ing a fringe of fine hairs. 



I have examined some twenty specimens of this species from the entrance to the 

 gill-chambers of two deep-sea crabs. 



Specimens. 



-f 0- Gill-chambers of Geryon afinis. Stat. 248 (Lat. 8° 37' N., Long. 75° 37' 30" 

 E., Laccadive Sea), between 224 and 284 fathoms. (S.S. " Investigator.") 



~fo~ Gill-chambers of Geryon guinquedens. " Martha's Vineyard " (off coast of 

 New Jersey, U. S. A.), 328 fathoms. (Smithsonian Institution.) 



Remarks — 



This species is variable as regards the exact form of its valves, the colour of the 

 membrane, the relative lengths of the capitulum and peduncle, and the proportions of 

 the latter. The lower branch of the scutum is sometimes broadly triangular, occa- 

 sionally almost Hnear, the outline of the tergum differs greatly in different individuals 

 and the carina sometimes ends practically at its lowest point and is sometimes pro- 

 duced into horizontal branches, which may underly the extremity of the basal 

 branches of the scutum. The specimens from Geryon guinquedens have a deep orange 

 colour and are very opaque, while those from G. aßnis are colourless and much more 

 translucent. In all, the valves are yellowish and apparently contain a large proportion 

 of chitin. Speaking generally, I may say that both the peduncle and the capitulum 

 are more slender in older than in young individuals, in which the former is often some- 

 what narrowly oval, while in older (or at any ratelarger) examples it is broadly trian- 

 gular. Even the narrow, oval individuals, however, often bear ova. There is one 

 character shown by some individuals among those from Geryon quinquedens (viz. , 

 the transverse fission of the carina) which seems to justify them being considered a 

 distinct variety, for which the name var. fissicarina is proposed. 



