244 



posterior gnathopoda in the 2 sexes. As in the other species of the present 

 genus, the mandibles are wholly wanting in any trace of a palp. 



Occui'mirc. As to habits, this species is a true deep-water form, 

 only occurring in greater depths, from 80 to loO fathoms, especially in the 

 region of the deep sea corals. I have met with it rather sparingly in a 

 few places off the west coast of Norway, Hardangerfjord, Bekkervig, and 

 quite recently also in the Trondhjemsfjord, where it occurred in one place 

 (Rodbjerget) rather abundantly, among Loplielia prolifci-a. Out of Norway 

 it has not yet been recorded. 



Gen. 2. Probolium, Costa, 1853. 



Body of female comparatively strongly built, with large and deep 

 coxal plates; that of male somewhat more slender. Antennae of moderate 

 size, subequal in length. Anterior lip as in Stenothoe; posterior lip with the 

 inner lobes coalesced. Mandibles having a distinct, though rather small, 

 3-articulated palp, the terminal joint of which is extremely, minute and 

 provided with only a single apical seta. First pair of maxillee with the 

 palp well developed and distinctly biarticnlate. Maxillipeds with the basal 

 lobes comparatively larger than in Stenothoe, broadly rounded at the tip, and 

 separated until the base. Grnathopoda rather unequal, the anterior ones 

 being very small and imperfectly subcheliforrn, the posterior ones power- 

 fully developed, with the meral joint, as in Stenothoe, triangularly produced 

 below, propodos very differently shaped in the 2 sexes, in female distinctly 

 subcheliform, in male much produced, and without any distinctly defined 

 palm, dactylus very long and curved. The 2 anterior pairs of pereiopoda 

 somewhat unequal, the 2nd pair being much stronger than the 1st; the 3 

 posterior pairs comparatively short and stout, with the meral joint rather 

 expanded, and produced at the infero-posteal corners to a triangular lobe, 

 basal joint of the 2 last pairs laminarly dilated. Uropoda and telson about 

 as in Stenothoe. 



Remarks. - This genus, established by Costa, is somewhat intermediate 

 in character between the genera Stenothoe and Metopa. With the former it 

 agrees in the structure of the 1st pair of maxillae, the palp of which is 

 distinctly biarticulate, in the basal lobes of the maxillipeds being separated 

 until the base, and in the triangularly produced form of the meral joint of 

 the posterior gnathopoda. On the other hand it approaches the genus 

 Metopa in the structure of the mandibles, which are provided with distinct 



