captured in Rio Janeiro. 35 1 



extending along the middle of the upper part, which is broadest 

 in the posterior region ; the sides are marked with a few brownish- 

 black spots, and oblique confluent lines of the same hue occur 

 on their posterior half; a broad band, composed of brownish- 

 black spots, extends along the middle of the under part, and 

 terminates in an angle at the spinners, which have a pale-brown 

 hue ; on the outer side of each branchial operculum there is a 

 short black streak ; and the colour of the sexual organs, which 

 are rather prominent, with a small triangular process whose 

 acute vertex is directed forwards, is brownish black. 



Family Salticid^e. 



Genus Salticus, Latr. 



Salticus placidus. 



Length of the female ^th of an inch ; length of the cephalo- 

 thorax g ; breadth f ^ ; breadth of the abdomen A ; length of 

 a posterior leg ^ j length of a leg of the second pair ^. 



The cephalothorax is large, glossy, somewhat quadrilateral, 

 sloping abruptly at the base, and projecting a little beyond the 

 falces in front ; it is of a brown-black colour, the cephalic region 

 being the brownest, and has a narrow band of white hairs on the 

 lateral margins. The minute intermediate eye of each lateral 

 row is nearly equidistant from the eyes constituting its extremi- 

 ties. The falces are small, conical, vertical, armed with a few 

 teeth on the inner surface, and are of a red-brown colour. The 

 maxillae are straight, and enlarged and rounded at the extremity; 

 and the lip is oval. These organs are of a brown hue, the ex- 

 tremity of the former and the apex of the latter having a pale 

 yellow-brown tint. The sternum is oval, and of a brown-black 

 colour. The legs are moderately robust, and provided with 

 hairs and sessile spines, two parallel rows of the latter occurring 

 on the inferior surface of the tibise and metatarsi of the first and 

 second pairs ; the fourth pair is the longest, then the first, and 

 the second pair is the shortest; each tarsus is terminated by 

 two curved, minutely pectinated claws, below which there is a 

 small scopula; they are of a very dark-brown colour, the meta- 

 tarsi and tarsi of all, and the coxa? and base of the genual joint 

 of the third and fourth pairs, having a yellowish-brown hue. 

 The palpi are short ; the humeral joint has a dark-brown hue, 

 that of the cubital, radial, and digital joints being yellowish 

 white. The abdomen is oviform, pointed towards the spinners 

 (which are prominent), convex above, and projects over the base 

 of the cephalothorax ; it is sparingly clothed with hairs, and of 

 a brown-black colour; a white band, curved round the anterior 

 extremity, extends along each side more than half its length, 



