SABELLIDES AND SERPULIDES 287 



ADDENDA. 



The following notes, which with a few exceptions relate to forms 

 previously mentioned, were made after the foregoing pages were set 

 up, therefore too late to have them inserted in their proper places. 



Genus Metalaonome nov. (See pp. 178 and 192.) 



Branchial lobes elongated ventrally and spirally coiled only in retrac- 

 tion. Interbranchial membrane inconspicuous or wanting. Collar 

 four-lobed, with ends widely separated on the back. Superior setae 

 and inferior collar setae regularly tapered blades ; inferior setae back of 

 collar, short oblanceolate. Avicular uncini only in all the tori of the 

 body. 



Lo Bianco ( 1 893) described the species Bispira martce as having 

 the elongated branchial lobes forming spirals of two or three turns, but 

 in the figure he has represented them as simple, similar to those of 

 Sabella, so that probably, like species of that genus, this one has them 

 spiral only in retraction. The branchiae, numbering between 80 and 

 90, are very long (about one half as long as body) and slender, with 

 seven series of dark color spots forming bands. 



The body is short and stout, of about 80 segments, of which 8 belong 

 to the thorax. 



The collar is four-lobed, open on back with widely separated ends. 

 Setae on the collar and superior setae on the other thoracic segments 

 very narrow, regularly tapered blades ; inferior setae back of collar, 

 short and broad oblanceolate. Avicular uncini only in all the tori of 

 the body. 



Genera Schizocraspedon and Glossopsis nov. (See pp. 179 and 225.) 

 Grube (1878) placed his two new species H.furcifera and H. 

 minax in the genus Hydroides, with which they have strong affinities, 

 but the very remarkable development of the opercula, described on p. 

 225, would at once distinguish them from typical species of that genus ; 

 hence they have been respectively referred to the two new genera 

 Schizocraspedon and Glossopsis. 



Genus Protoplacostegus nov. (See pp. 179 and 226.) 



Mclntosh (1885) described and figured his species Placostegus 

 morchii as having a primary, somewhat cup-shaped operculum with 

 horny plate on the end of one branchia and an undeveloped secondary 

 one on the end of another branchia. The setae short and broad at base 

 with tapered blades (no collar setae were found) . Uncini with few (6 



