76 

 Dimensions — 



DR. N. ANNAN DALE 



60 



mm. 



45 



>> 



16 



>» 



81 



>> 



24 



>> 



Length of Capitulum 

 Breadth of ,, 

 Thickness of „ 

 Length of Peduncle 

 Diameter of ,, 



Appendages, etc. — 



First Cirrus widely separated from second ; its basal joint broad, much compressed 

 dorso-ventrally ; the two rami highly differentiated ; anterior ramus broad and rather short, 

 strongly lobed on its posterior, more feebly on its anterior margin ; the ventral surface of 

 its anterior half convex and covered with short silky hairs, that of the posterior half con- 

 cave and bare except for a marginal fringe of similar hairs. Both surfaces of posterior 

 ramus convex, the anterior and posterior halves less differentiated, the whole of the ven- 

 tral surface hairy; dorsal surface fitting into concave posterior half of ventral surface of 

 anterior ramus ; the whole ramus longer than the anterior by three joints, pointed at free 

 extremity. Second to Sixth Cirri offering no peculiarity except that the setae which fringe 

 their anterior margin are extremely fine and rather short. Anal Appendages short and 

 very slender, with nine joints and a terminal bunch of fine hairs, the tip of which reaches 

 the centre of the third joint of the sixth cirrus. Penis absent. 



Month- Parts— 



Labrum prominent, strongly bullate, constricted at the base. Mandibles large, 

 with 5 main teeth ; two smaller teeth between the outermost and 

 the next large one ; the four innermost main teeth subequal, 

 the outermost simple, triangular. Maxilla: with free edge 

 concave towards outermost spine; spines numerous, feebly 

 differentiated, outermost spine and several near the centre lar- 

 gest. 



Scalpdlum /nerme, Observations — 



The anus is unusually large in this species, being a vertical 

 slit with swollen lips. The whole body is of a uniform yellowish tint and there is no 

 trace of pigmentation at any point on the surface. These characters may be of impor- 

 tance in diagnosing some of the deep-sea forms. 



S. inerme differs from any species of the genus previously described in having more than 

 four main teeth on its mandible. Gruvel in his Monographic des Cirrhipedes, (Paris, 1905), 

 in defining the genus says, "Mandibles avec trots on quatre dents," while Darwin wrote, 

 " The mandibles have either three or four main teeth, generally with either one or two small 

 teeth intermediate between the first and second large teeth," (A Monograph of the Cir- 

 ripedia, Lepadidce, p. 220, 185 1). Considering the other peculiarities of the species, there 



