170 spio. 



Leuckart, Oolobranchus ciliatus, Keferstein, Uncinia ciliata, De Quatrefages, and Scoliolepis 

 vulgaris (pro parte), Malmgren, and moreover approached the Spio bombyx of Claparede. 

 The ova of this form, with their pearly specks, were studied by the author, who describes 

 what he calls pre-fecundation. This occurs a short time before maturation, a small mass 

 applying itself to the nucleolus and fusing with it. 



The British species of Spio range themselves in two groups, viz. : (1) those agreeing 

 with the two species described by Otho Fabricius in having a conical or bluntly-conical 

 snout and two eyes, and (2) those with a bifid snout and two or three pairs of eyes. A 

 more extended examination of this group is necessary, but meanwhile those with the 

 entire snout may for convenience be placed under the old term Spio, whilst those with the 

 bifid snout may be distinguished by the title Euspio. The imperfection of many of the 

 specimens renders the task of identification difficult, and hence the literature of the group 

 is more or less confused. Talented authors, like Mesnil, have been unable to satisfy them- 

 selves as to the precise species described by Fabricius, and much obscurity still remains. 

 Thus no form subsequently mentioned agrees with the Spio seticomu of Fabricius 

 (Die borstenformige Spio) which has a greyish body with pale bands beneath, a conical 

 snout, two eyes, branchias from end to end, and two milk-white or pinkish ovate anal cirri. 



1. The first is Spio D, St. Andrews, which can only be briefly alluded to at present. 

 Plate XCVIII, fig. 8— head; Plate CVI, figs. 8 and 8a— stiff, spine-like bristles; Plate 



CX, fig. 11 — capillary bristle. 

 A fragmentary form, the condition of which is unsuitable for specific characters. 



Synonyms. 

 1862. Oolobranchus ciliatus, Keferstein. Zeitschr. f. wiss. Zool., Bd.xii,pp. 118 — 120, Taf. x, figs. 12—18. 

 1881. Spio crenaticornis, Langerhans. Canarisclie Annel., Nova Acta Acad. Leop. -Carol., Bd. xlii, 



p. 114. (Eggs red.) 

 = Aonis Wagneri, Leuckart and Pagenstecher. Beitr. Wirbellosen Th.,p. 156. 

 1909. Spio D, Mcintosh. Ann. Nat. Hist., ser. 8, vol. iii, p. 164. 



Habitat.— -From the deep-sea fishing boats, St. Andrews, October, 1868 (B. Mcintosh). 



A softened and fragmentary narrow, elongated form measuring at least two inches 

 in length, and apparently having subulate branchiae from end to end. The snout appears 

 to be bluntly rounded (but the condition makes even this uncertain) and to have two eyes 

 anteriorly (Plate XCVIII, fig. 8). 



The dorsal division of the foot (Plate CVI, fig. 8) has long tufts of very finely tapered 

 capillary bristles, without wings, and posteriorly they increase much in length. The 

 ventral division has a shorter series of stronger bristles with a distinct hook at the point 

 (Plate CVI, fig. 8 a), to which the tip curves forward, and some groups consist entirely of 

 these in the pulpy preparation. 



2. Spio G. Plate XCVII, fig. 10— tail; Plate C, fig. 12— foot; Plate CV, fig. 12— hook; 



Plate CVI, fig. 10— bristle. 

 Specific Characters.— Read rounded in front, forming a bluntly-pointed snout, with 

 the mouth opening a short distance behind the tip ventrally. The two tentacles are of 



