284 



in form, its tip jutting out above the insertion of the dactylus as a triangu- 

 larly pointed projection setous at the edge, palm somewhat curved, and de- 

 fined below by a very slight obtuse angle, its edge minutely serrulated 

 throughout; propodos of male still larger than in female, and more dilated in 

 its proximal part to receive the powerful muscles moving the dactylus. Pe- 

 reiopoda nearly equal in size, and provided with very short marginal spi- 

 nules, dactylus in all very small, basal joint of last pair oval, posterior edge 

 serrated, and strongly curved in the middle. Last pair of uropoda with the 

 rami much shorter than the basal part. Telson \ 7 ery elongated, about 3 times 

 as long as it is broad at the base, and gradually tapering to an acuminate 

 point. Body of a pale flesh-colour, with slight transverse bands of a somewhat 

 darker hue, ova in the marsupial pouch of a fine grass green colour. Length 

 of adult female reaching 14mm, that of male 15mm. 



Hewai'ks. By the peculiar structure of the gnathopoda this form 

 is so highly characterised as to be at once recognized from most other Am- 

 phipoda. Also from the following species it may readily be distinguished, by 

 several well-marked characteristics. Of the exotic species the L. M/crsi of 

 Stebbing is that which comes nearest to the present form. 



Occurrence. - - Off the south and west coasts of Norway this species is 

 far from being rare, occurring even in some places, as in the Trondhjemsfjord, 

 in great abundance. It is found in depths varying from 30 to 150 fathoms, 

 now free, now semiparasitic in the branchial cavity of Ascidise. 



Distrilufioi/. - British Isles (Montagu and others), Kattegat (Meinert), 

 coast of France (Chevreux), Mediterranean (Costa), Azores (Barrois), Green- 

 land (Hansen). 



2. Leucothoe Lilljeborgii, Boeck. 



(PL 101, fig. 2). 

 '' Lilljeborgii, Boeck, Forhandl. Skand. Naturf. Sde Mode 1860. 



Syii: Leucothoe artieulosa, Lilljeb. (non Mont . 



Leucothoe furina, Norman & G. O Bars (11011 Savigny). 

 Leucothoe imparicornis, Norman 



Body even somewhat more slender than in the type species, and less 

 tumid. Cephalon nearly twice as long as the 1st segment of mesosome, fron- 

 tal projection somewhat more produced than in L. *j>i>/ir(ii-)>, lateral corners 

 evenly rounded. First pair of coxal plates narrowly rounded at the anterior 

 corners, 4th pair pentagonal in form, anterior corners produced to an acute 

 point. Last pair of epimeral plates of metasome forming at the lateral cor- 

 ners a strong, recurved, acuminate projection denned above by a deep sinus, 

 I posterior edge strongly arcuate. Eyes rounded triangular in form, pigment 



