two new Sjjecies of Scyllaricla3. 229 



This genus is most nearly allied to Ibacus and Parrihacus, 

 but is veiy distinct from both of them in the entire lateral 

 margin of the carapax, the closing of the orbits in front, and 

 the form of the rostrum. 



Evihaciis 2yTincepSj sp. noy. 



Whole upper surface verrucose and nearly naked ; five low, 

 tuberculose elevations on the median line of the carapax, of 

 which one is at the base of the rostrum, two on the gastric 

 region, one on the anterior part of the cardiac, and one on the 

 posterior margin ; similar elevations on the middle of the se- 

 cond and third segments of the abdomen, and a very slight 

 one on the fourth. Carapax strongly convex transversely ; 

 the anterior margin nearly straight, except at the lateral angle, 

 where it is slightly curved forward ; lateral margin strongly 

 curved, with a broad notch at the cervical suture, behind 

 which the margin is very slightly obtusely and irregularly 

 toothed. Antennae together as broad as the anterior part ot 

 the carapax ; the outer margins coarsely and irregularly 

 serrate and their outline forming the segment of a circle. 

 Everywhere beneath naked and nearly smooth. External 

 maxillipeds with the outer margin of the merus divided into 

 a number of slender processes. Legs so short that when bent 

 forward in their natural position they are concealed beneath 

 the expansions of the carapax ; those of the first and second 

 pairs with the superior angle of the merus raised into an ob- 

 tuse crest ; dactyli of all the legs short and stout, in the female 

 those of the posterior pair closing against a process from the 

 propodus. Abdomen with the lateral projections of the se- 

 cond, third, and fourth segments long and rather acutely 

 pointed, those of the fourth shorter and triangular at tip ; 

 lamella of the terminal segment half as long as broad. Whole 

 length of body 14 in. ; length of carapax, including rostrum, 

 5'8 ; breadth of carapax 7'9. 



A single female specimen of this remarkable species, the 

 first of the Scyllaridge discovered upon the west coast of Ame- 

 rica, was sent from La Paz, Lower California, by Capt. Jas. 

 Pedersen. 



Arctus americanus^ sp. nov. 



Carapax as broad as long, median crest high, covered with 

 low squamiform tubercles, tridentate, the anterior tooth small 

 and situated halfway between the front and the second tooth ; 

 lateral crests very high, anterior portion with two teeth above 

 the eye and separated by a deep notch from the posterior por- 

 tion, which is covered to the lateral margin with low squami- 

 form tubercles; depression between the median and lateral 



