538 r. ^Y. gamble and j. h. ashwoeth. 



of Ai-enicola (A. Claparedii) is without otocysts, but all 

 have at least five pairs of nephridia, and iu all species of this 

 genus the gonads arise directly from the peritoneal cover- 

 ing of the vessel supplying the nephrostome. On the other 

 hand, Maldanidfe have three to four pairs of nephridia (in 

 segments 5 — 8), they have no otocysts, and in so far 

 Branchiomaldane agrees with them. No Maldanid, how- 

 ever, is known which possesses gills, though Johns tenia 

 clymenoides has small processes on the posterior segments 

 which have not been fully described, and which may prove to 

 be respiratory, though their multiple character in each seg- 

 ment renders it unlikely that they are homologous with the 

 gills of, e.g., Arenicola or Branchio maldane. The account 

 of the origin of the gonads by Cosmovici (1879) in Clymene 

 is the only record we are aware of in the family, and shows 

 that they are as intimately connected with the nephridial 

 vessel as in Arenicola. 



On the whole the evidence seems to show that Branchio- 

 maldane should provisionally be included as a distinct genus 

 in the Arenicolidae. 



The characters of the family thus constituted may be stated 

 as follows. The body is cylindrical, elongated, and divisible 

 into two or three regions in addition to the prostomium. 

 The gills are present either in the middle region, in which 

 case the posterior section is acheetous as well as abranchiate, 

 or in the middle and posterior sections, which together form a 

 single chtetiferons region, but they are never present in the 

 anterior seven segments. In structure, the gills of Branchio- 

 maldane represent an arrested stage of A. marina. The 

 prostomium though small is distinct, and is bounded pos- 

 teriorly by the ciliated groove or nuchal organ. In shape it 

 is conical or trifoliate, with lateral hollow lobes. The pein- 

 stomium and next following segment appear to have fused in 

 the adult into an achjetous mass. This region, hoAvever, in 

 post-larval stage is subdivided, and bears a vestigial seta 

 (as shown in A. marina by Benham, and in A. ecaudata 

 by Mesnil) which we have failed to demonstrate satisfactorily. 



