ON A NKW SPECIES OK SCLEROOHKJLUS. 297 



base of (lie lurk. The prongs, \vliicli arc unci|iial in length, arc usually curved, their 

 fine tips pointing away from each other. In the anterior ami middle segments the 

 prunes are about 50/u ami :'>."i, in length respectively, ami iu the posterior segments 

 :il >out 4(V and 25^. Kadi prong hears along the inner edge of its proximal tlirce- 

 fourtlis a series of regularly-placed pointed processes. Only tin- fork and a short 

 portion of the shaft proximal to it project beyond the lips of the chsetal sac. In the 

 middle region of the body there arc aliout eight to twelve furcate cha't;e in cadi of 

 the rami of the parapodia. 



SYSTEMATIC POSITION' OF THK SPECIMEN FROM SCOTIA BAY. 



The characters of the prostomium, parapodia, and di;rta', and especially the 

 presence of the distinctive furcate di.-ct:o, show dearly that the specimen described 

 above belongs to the family Scalibregmidse. It is referable to the Scalibregma- 

 section * of the family, for the body is sub-fusiform and the prostomium T-shaped, 

 its lateral angles being drawn out to form short tentacular processes. To this section 

 of the family belong the following genera : Scalibregma Rathke, Pseudoscalibregma 

 Ashworth, Sclerocheilus Grube, Asclerocheilus Ashworth, and Oncoscolex Schmarda. 



The Scotia Bay specimen differs from Scalibregma in several striking respects, 

 e.g. the absence of gills and dorsal cirri, the ventral cirri are much more slender, 

 and there are stronger choetre in the first and second notopodia, whereas such chaetse 

 are not present in Scalibregina. Further, Scalibregma rarely possesses eyes.t 



The genus Pseudoscalibregma was suggested by the writer J to contain certain 

 little-known, abranchiate worms resembling Scalibregma in general appearance, but 

 their real relationship to Scalibregma remains to be ascertained. These worms 

 appear to agree in their external features with Scnfibrci/ina', except in regard to the 

 absence of gills, and so differ from the Scotia Bay specimen in the parapodial and 

 chsetal characters mentioned above. 



The characters of Axderwlu'iliix are little known, but the single species 

 Asclerocheilus imtervnedius (==Lip6bra,nchius intermedius Saint-Joseph) referred 



* See the olassitication suggested liy the writer in ',"""'' -fonrn. Micr. Sri., vol. xlv (1901), p]i. 296, 297. 



t I have examined about sixty specimen* of Nr,j//7,,v ( //m/ varying in length from I nun. to .">*! mm., and including 

 five epitokons examples. Eyes are present in only t.wu specimens, both onlin.-irv non-cpilokoiis forms. For one of 

 llicsc spccimi'iis, which lias been in my possession twelve years, I am indebted to Dr E. J. AI.LKN, F.R.S., who 

 collected it near Plymouth ; for tin- othrr, colh-i'ted in 1!11 .it (';i\< \,i-v\, near Cherbourg, I have to thank Professor 

 F.vrvEL, who, on finding that this specimen possessed eyes, kindly si-nt. it to me for examination. Moth specimens 

 are similar in size, lint only one the Plymouth specimen is complete; it, is 3d mm. in length. In both, the eye 

 are on the right and left sides of the prostominm, and are wide apart, i.e. do not approach each other like those of 

 Kderoclieilits. 1 have stained and cleared the Plymouth specimen, which exhibits on each side two eyes adjacent to 

 each other, composed of a series of closely associated simple eyes, which in section are found to lie similar in structure 

 to those of Sclerncheilit*. 



I See Quart. Jnrn. Min: Xn., vol. xlv (1901), pp. 291, 292. 



The genus Lipobranchiti* founded by Messr.- CCNXINCIIAM ami I;\MV;I to contain the species L. jrffnysii 

 ( = Eumenia jeffrujfii M'Intosh) cannot well contain also /,. int, nii>-ilin< Saint-Joseph, wliich differs from the former 

 in several respects, but especially in the nature of the ch.i t.i of tin- first, and sei-emd notopodia. A thorough revision 



(ROY. soc. KIIIN. TUANS., \oi. i., 409.) 



