Gatt)/ }fnrine Laboratori/, St. Andrews. 2(15 



is minute (in some inilistiii;^ui.4luible) and closely attaclicd to 

 the base of the short and broad branchial process, whicii 

 shows only a slij^ht concavity externally. In translucent 

 preparations this lamellar branchia shows a crenate mem- 

 branous border antl lar^e central trunks. The setigcMons hdjo 

 is prominent ami in side view forms a |)rojecting lamella both 

 above and below the spine. No fillet occurs at the base of 

 the barred bristles. The bristles arc of moderate length, 

 with a curve backward. Both the barred and the elongated 

 kinds are somewhat slender, the former being marked by clo^e 

 transverse barstmd tapering to a fine point (PI. VIII. fig. 4) ; 

 the latter also slender and ta|)ering to a dedicate tij), the blade 

 with distinct serrations (rows of spikes) on the expaiided 

 region above the shaft (Pi. VIII. tigs. 5 & G), the tip appa- 

 rently smooth. The serrations, however, are easily removed. 



The inferior division stands widely apart, without a lamella 

 or occasionally only a trace. It has a blunt point and extends 

 further outward tlian the dorsal. The spinigerous lobe is 

 flattened and conical, with the spine at the apex. The fillet 

 at the base of the barred bristles sends a process superiorly. 

 The inferior cirrus is of moderate size and conical in shape. 



Posteriorly the dorsal and ventral lobes of the feet b-icom^ 

 prolonged and acute. A trace of the dorsal lamella is still 

 visible. The branchia, however, has shrunk to a minute 

 process beneath the small cirrus. The inferior division has 

 approached considerably nearer the upper and extends as a 

 long pointed lobe half its length beyond the upper, and the 

 ventral cirrus is carried outward nearly in a vertical line with 

 the branchia. 



The feet and bristles were studded with numerous examples 

 of a whitish clavate ecto-parasite like Loxosoinu, which, 

 however, had a series of spiue-like processes, either lateral or 

 terminal. 



Nephthys lawrencii, sp. n. 



Dredged on Bradelle Bank, Gulf of St. Lawrence, Canada, 

 1873 ; at Stat. A 1, 1«72 ; and off Port Hood, 1873. 



The head is somewhat longer than broad, though in extru- 

 sion of the proboscis it becomes shield-shaped. A short and 

 somewhat flattened conical tentacle comes from each angle of 

 the rather narrow and straight anterior margin. The second 

 or ventral tentacles, which are separated from tlie first by a 

 short interval, are similar in shape but scarcely so large. 

 Two slight elevations occur on each side of the median line 

 posteriorly. In the ordinary position of the proboscis within 

 the body the ventral cirrus of the first foot shows a somewhat 



