648 



and such specimens are generally of smaller size and often of a dark red 

 colour, in accordance with their surroundings. Though devoid of any nata- 

 tory limbs, the animal is enabled to move rather quickly through the water 

 by rapidly repeated bends of the body. 



Distribution. British Isles (Sp. Bate), Bohuslan (Bruzelius), Kattegat 

 (Meinert), Dutch coast (Hoek), coast of France (Chevreux), Mediterranean 

 (P. Meyer), Adriatic (Heller), Azores (Barrels). 



Gen. 2. Protella, Dana, 1852. 

 Syn.: ^Egina, Boeck (part). 



Body very slender, and more or less spinous, with a slight impression 

 dorsally between the cephalon and 1st segment of mesosome, the last 2 body- 

 segments short. Superior antennae slender and elongated; inferior antenna 

 with the flagellum short, biarticulate. Mandibles normally developed, with 

 the molar expansion well marked, and the palp rather large. Maxillipeds 

 with the masticatory lobes larger than the basal ones, and only armed with 

 a few scattered bristles. Gnathopoda very unequally developed and of nearly 

 same structure in the 2 sexes, the anterior ones being rather small, the 

 posterior ones very much elongated, with the propodos exceedingly large and 

 having the palmar edge divided into acute lappets. The 2 anterior pairs of 

 pereiopoda only present as very small, uniarticulate rudiments at the bases 

 of the branchial lamellae; the 3 posterior pairs well developed, the ante- 

 penultimate pair being however somewhat less strong than the last 2 pairs, 

 which are distinctly subcheliform. Branchial lamellae only present in the 

 3rd and 4th segments of mesosome. Urosome very small, and without any 

 distinct appendages. 



Eemarlcs. This genus was established in the year 1852 by Dana, 

 and was characterized by the presence of distinct, though small rudiments 

 of the 2 anterior pairs of pereiopoda. The genus was also accepted by Sp. 

 Bate, whereas Boeck combined it with the genus j&yina of Kroyer. In out- 

 ward appearance, as also in the structure of most of the appendages, both 

 genera are certainly closely related, but ought, in my opinion, to be kept 

 apart on accout of the above-named characteristic, which was overlooked 

 by Boeck, as also because the urosome exhibits in both a rather different 

 structure. Several species also of this genus have been described, some of 

 kvhieli appear to be well marked. To the fauna of Norway belongs only 

 a single species, to be described below. 



