MUSEUM OF COMPAKATIVE ZOOLOGY. 15 



are dichotomously branched and united with one another, so as to give origin 

 to small, smooth perforated plates. There is no doubt that Psolus Fourtalesi 

 is nearly allied to Psolus squamatus. 



Habitat. Lat. 41° 24' 45" N., Lon. 65° 35' 30" W. (1880) ; depth 1242 

 fathoms ; ten specimens. 



Psolus braziliensis, n. sp. 



Figrure 7. 



The body is like that in Psolus phantapus. The length, including the ex- 

 tended mouth, is 32 mm. The color is whitish. Two ventral tentacles are 

 always much smaller than the eight remaining. The ventral rectangular sole 

 carries three series of pedicels, the two lateral composed of about four rows, 

 the middle of only two. Anteriorly and posteriorly the series run together. 

 The exterior row of each lateral series is placed in the margin of the body. 

 The dorsal body-wall is rather soft and covered with scales, which overlap 

 very little. The mouth is not closed by valves, but by a series of elongate 

 triangular scales with a very acute free angle; the anus is closed by similar 

 smaller and more irregular scales. Outside of the scales, the dorsal perisome 

 contains minute conical cup-like tables, and large, elongate conical table-like 

 deposits made up of a more or less irregular network with the free end spinous. 

 The sole is strengthened by small, scattered, smooth plates with an uneven 

 margin and perforated by four or more holes. 



Scattered among the dorsal deposits small, highly reduced "pedicels" are 

 found, which are strengthened by a small but very well marked perforated 

 terminal plate, and by well-developed irregular plates. There is no doubt 

 that these are true pedicels, and thus it is a very interesting fact, that some 

 species of Psolus have retained the dorsal pedicels, though in a very rudi- 

 mentary state. The scales seem to present some larger pores, through which 

 the pedicels communicate with the ambulacral system (?). 



Habitat. Porto Seguro; two specimens. 



Psolus, sp. (?). 



The body, which has a length of 12 mm., is very flattened and covered with 

 scales on the dorsal surface ; these decrease considerably in size towards the 

 oral and anal openings, which consequently are completely devoid of valves. 

 The general appearance of the body closely resembles that of Psoitis Pourtalesi. 

 The pedicels form a double row round the sole, the exterior row being placed 

 in the margin of the body. The odd ambulacrum is naked. The sole is 

 strengthened with small plates of a more or less symmetrical appearance ; the 

 most symmetrical are oval, with four holes, and twelve knobs or rounded 

 prominences arranged in the margin; in addition, the surface itself of the 



