101 



specimens described by Leach and Montague have the third 

 maxiHipedes pediform. A large number of authors, however, 

 say that the third maxiHipedes are opercuUform, and St ebbing 

 has seen specimens from Jersey, in which they could not be called 

 pediform, and in which the telson was more quadrate than in 

 the original Devonshire specimens. These specimens in which 

 the third maxiHipedes are operculif orm , really belong to a differ- 

 ent species which has been mistaken for the genuine C. sub- 

 teiranea. Borradaile, (1903) has given this second species the 

 name of C. Stebbingi. This species belongs to the subgenus, 

 Callichirus, Stimpson, whereas the real C. subterranea of Montague 

 and Leach belongs to another subgenus, Cheramus, Spence Bate. 

 The two species may be separated as follows : — 



Third maxiHipedes pediform, slender ; telson 

 as long as the inner branch of the uropods^ 



C. subterranea. 



Third maxiHipedes operculif orm , third and 

 fourth joints very broad, last three joints 

 slender ; telson distinctly shorter than the 

 inner branch of the uropods, . . . . C. Stebbingi, 



It is not certain which species Bell had before him when he 

 wrote his description. Under " Generic characters " he says, — 

 " External pedipalps with the second and third joints very 

 broad, constituting when in contact a broad oval disk, and 

 terminating in a small seta formed of the last three joints." 

 Farther on, however, he says; — " The external pedipalps are 

 rather broad, pediform." 



I have compared Irish specimens with two from the Bay of 

 Naples, and find complete agreement between them. 



The species has been several times described under the name 

 of C. subterranea, and so it will be sufHcient to give here merely 

 a brief summary of its chief characteristics. 



Carapace smooth, less than half as long as the abdomen. 

 Linea thallassinica and cervical groove well marked. Rostrum 

 practically absent, represented by at most a minute projection 

 between the eyes, which are pressed close together. Corneal 

 surface black. Antennules short, lash-like ; peduncle as long as 

 flagella. Antennae considerably longer than the carapace. 

 Third maxiHipedes have the ischium and the menis very broad 

 and flattened, so that they form an opercular plate when closed. 

 Chelipeds extremely unequal, sometimes the right being the larger, 

 sometimes the left. The last three joints of the large cheliped 

 are very massive, and very much broader than the slender basal 

 joints, which support them. The inner side of the merus bears 

 a large curved process, the edges of which are slightly serrate, 

 and the tip of which is sharp. Lower border of ischium slightly 

 serrate. Lower margin of carpus and propodite fringed with 

 setae, w^hich are also present en the upper margin of the dactyl, 

 which also bears tufts of bristles. The second pereiopods are 



