66 CRUSTACEA MALACOSTRACA. II. 



differences in the shape of the molar processes of the mandible, in chelipeds, thoracic legs, pleopods 

 and nropods. Bnt being unable to say anything about the mandibles in several interesting species, because 

 my material is too small, and being in doubt whether some of the characters are only of specific value 

 or ought to be considered of higher importance, I confine myself to dividing the species described or 

 mentioned in this report into four groups and two of these groups into sub-groups. This arrange- 

 ment may, I hope, not only facilitate the determination of species but besides afford a general view 

 of the relationships of the various species. It may be stated that the divisions are founded exclu- 

 sively on the females, because in several species the pleopods are rudimentary or wanting in this sex 

 but well developed in the subadult males. 



Group a. Uropods long, with botli rami two-jointed and the exopod considerably shorter than 

 the proximal joint of the endopod. Pleopods in the females zvell developed, biramous, with long seta-. 

 Animals moderately slender or somewhat robust. 



The animals of this division, which may be named the Sarsii- or long ire/// is-group, are some- 

 what uniform in general aspect and allied in several features. Sars' figures of the female of his L. 

 longiren/is (= L. Sarsii H. J. H., not L. longiremis Lilljbg.) convey a fair idea of the aspect of the forms 

 of this group. The body is moderately slender. The antennae are seven-jointed, as fourth and fifth 

 joints are separated by a well developed articulation. The basal joint of the chelipeds have the po- 

 sterior protuberance well developed, with its posterior margin free and rounded. The thoracic legs 

 are moderately slender, with long or moderately long spines; the three posterior pairs with seventh 

 joint moderately long, considerably or much longer than the claw and both combined as long as or 

 longer than the sixth joint. This group may be divided into three subdivisions. 



a. The movable finger of the chelae serrate along the anterior (upper) margin. 



Fifth abdominal segment without any hastate process. 



Species 41 — 43. 



/9. The movable finger of the chelae without serration along the anterior margin. 



Fifth abdominal segment without any hastate process. 



Species 44 — 48. 



y. The movable finger of the chelae without serration along the front margin. 



Fifth abdominal segment with the ventral protuberance produced in a long 



acute process directed more or less backwards. 



Species 49 — 51. 



Group a, subdivision a ( v i d . above). 



41. Leptognathia multiserrata n. sp. 



(PI. VI, figs. 6 a— 6 e.) 



Female (without marsupium). General aspect as in L. Sarsii H. J. H. — Anteunulee slightly 

 more than two-thirds as long as the carapace. First joint nearly longer than the three others combined 



