UNCINEREIS SUBITA. 217 



article is very nearly as long as the proximal one and is about two thirds as 

 thick ; it is cylindrical, with the distal end strongly rounded. 



The peristomium above is bowed strongly forward over the base of the 

 prostomium. It is clearly shorter above than the prostomium and is, in the 

 median dorsal hne, very shghtly or not at all longer than the second somite, 

 than which at the sides it is obviously shorter, though ventrally decidedly 

 longer. On the ventral side it curves back as a broad projection into the second 

 somite, the sides of the produced area being concave, and the caudal margin 

 wide and straight. This caudal region is set off by a weak transverse furrow. 

 The ventral area of the prostomium is crossed by numerous fine longitudinal 

 sulci which are toward each side moderately obhque. The anterior margin is 

 straight, curving back slightly on the sides. 



The tentacular cirri are inserted as usual. The ventral ones are much more 

 slender and shorter than the dorsal, the anterior ones reaching to the thhd 

 somite and posterior to the fourth. The ceratophores are short, cyhndrical, and 

 a little thicker than the styles at base. The dorsal cirri have ceratophores that 

 greatly exceed those of the ventrals, that of the posterior dorsal also clearly 

 exceeding that of the anterior. The anterior dorsal reaches to the sixth or 

 seventh somite, the posterior dorsal to the twelfth or thirteenth. 



The metastomial somites decrease in length to the fifth after which they 

 remain of nearly uniform length. Each of the most anterior ones is bowed 

 conspicuously forwards at the sides. They are highly arched above, though 

 across the top somewhat depressed and with a weak median longitudinal sulcus. 

 They are strongly flattened ventrally, extending but slightly below the level of 

 the parapodia, and have a well-marked neural furrow. 



A parapodium from the middle region of the body is short and deep, the 

 dorsoventral diameter or depth exceeding the length. It is flattened in the 

 direction of the axis of the body, as usual. The undivided basal division is much 

 longer dorsally than ventrally, its distal side being oblique and straight. It 

 bears the usual four lobes. The notopodium shows a subcylindrical lobe, narrow- 

 ing toward the base and subconically distad, which lies below the setae, this 

 rising from a very low conical process of the basal division of the parapodium 

 much shorter than the infrasetal lobe. The infrasetal lobe is longer than the 

 crochets, but shorter than the other setae. The neuropodium projects as a 

 distinct subcorneal lobe as long as but thicker proximally than the infrasetal 

 notopodial process. At the distal end it presents a short, rounded, presetal 

 and a postsetal lip, which are equal in length, or nearly so. The dorsal lobe pre- 



