A new species of free-living nematode from the Firth of Clyde, Scotland P. J. D. Lambshead Department of Zoology, British Museum (Natural History), Cromwell Road, London SW7 5BD Introduction A new species of free-living marine nematode, Odontophoroides paramonhystera is described from a fine sandy beach in the Firth of Clyde, Scotland. It is similar to Odontophoroides monhystera (Gerlach, 1953) from which it differs primarily in having a precloacal supplement. Odontophoroides monhystera sensu Hopper, 1968, is renamed Odontophoroides hopperi nom. nov. Odontophoroides paramonhystera sp. nov. Figs 1,2, 3 &4 MATERIAL STUDIED. Eleven males and nine females, deposited at the British Museum (Natural History): Holotype-d 1 ,, BM(NH)198 1.6.42; Paratypes-d 1 , BM(NH) 1981.6.43-50 & 1981.6.59-60,$,^ BM(NH)198 1.6.5 1-57 & 1981.6.61-62. Also an 'en face' view of a juvenile was prepared, BM(NH)1981.6.58. In addition specimens of O. monhystera, collected by Dr S. Lorenzen (1973) and Drs G. Boucher & M. N. Helleouet (1977), were examined. LOCALITY. Low water spring mark, fine sandy beach, Scalpsie Bay, Isle of Bute, Scotland. MEASUREMENTS. See Table 1 . DESCRIPTION. Slender, colourless, worms. No pigment spots or ocelli seen in preserved specimens. Cuticle finely, transversely striated (Fig. 3a, b). Six papillae visible in 'en face' view (Fig. Ic, juvenile): whether R, or R 2 not clear. Four R 3 cephalic setae, about 1J head diameters long. Two fine subcephalic setae associated with the subventral R 3 cephalic setae in females; not observed in males. Six cervical setae present; two subdorsal and four sub-ventral, posterior subventral cervical setae more posterior in males than females. Stout lateral setae at base of amphids; about 15 //m long, but difficult to measure accurately due to the angle at which they project. Somatic setae in four irregular rows; length variable, but often longer in oesophagus and anterior gut regions. Amphids prominent, shaped like the head of a looped Shepherd's crook, with cuticularized borders; wider in males. Corpus gelatum displaced in about half of the male specimens but none of the females. Buccal cavity large, conical, cuticularized, with a complex arrangement of teeth (Fig. Ic, d). Six teeth present, bifurcate with a minor projection growing out of the main tooth. The four sublateral teeth are large and heavily cuticularized. Lateral teeth reduced to flat plates. Teeth attached at base to heavily cuticularized anterior section of buccal cavity (Fig. Id). Two subdorsal, cuticularized tooth-like projections present; no equivalent subventral structures. In some preserved specimens the mouth was open, partially everting the teeth. Oesophagus muscular, especially in region which surrounds posterior section of buccal cavity; bulbs absent. Excretory pore prominent, located opposite posterior half of buccal cavity. Cellular sac in close association with posterior of excretory cell (Fig. 2b); function unknown. Caudal glands present lying entirely posterior to the anus. Tail conical. Bull. Br. Mus. nat Hist. (Tool.) 42 (3): 149-155 Issued 27 May 1982
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