Prof. Owen on a new species of SeaL 331 



are represented ; m', lining membrane bearing impressions of the 

 rings. 



Fig. 29. A more highly magnified view of the extremity of the ovipositor ; 

 a, the rings. 



Fig. 30. A female P. Opilio, with the ovipositor and its sheath extruded 

 from the abdominal cavity. 



Fig. 31. The nervous system dissected out and detached from the body. At 

 the point where the branches from the abdominal ganglia commu- 

 nicate, the nervous fibre is observed to be thickened. 



Fig. 32. Muscles of the middle conjoined pair of eyes. 



Fig. 33. Respiratory system — the integument has been removed from the 

 dorsal aspect to expose the tracheae ; m s, muscular sheath of ovi- 

 positor, part of which is torn away to expose the true sheath be- 

 neath it ; ag, ag', nervous ganglia ; r m, retractor muscles ; o v, ovi- 

 duct; ch, basal joints of chelicerae; mp, maxillary palpi ; 1, 2,3, 

 4, coxal joints. The transverse part (t) of the thoracic ganglion 

 and the cephalic, giving off the optic nerve, on, are also seen in 

 their relations to the tracheal trunks on the left side of the figure ; 

 the second and third abdominal tracheae have been broken off, 

 leaving openings in the main tubes corresponding with their points 

 of origin. 



XLI. — Notice of a new species of Seal (Stenorhynchus serridens). 

 By Prof. Owen, F.R.S. 



In the small and very peculiar group of Seals characterized by 

 the subcompressed and deep-cleft crowns of the molar teeth and 

 by the diminutive claws, two species only have been recorded. 

 The one {Phoca leptonyoo^ Blainville) is the type of the genus 

 Stenorhynchus, F. Cuv.; the other, the sea-leopard of Weddell [Ste^ 

 norhynchus Weddellii, Lesson, ' Manuel de Mammalogie,^ 12mo, 

 1827, p. 200), has been described by Drs. Jamieson and Hamilton 

 (Naturalist^s Library, ^ Marine Amphibia ^), and distinguished 

 from the Stenorhynchus leptonyx, F. Cuv., by the more obtuse 

 tricuspid molars and the absence (?) of claws on the hind-fins, as 

 well as by the spotted hide. 



The skeleton of a seal " from a high latitude in the Australian 

 seas,^-* transmitted to the College of Surgeons by Dr. M^Cormick, 

 surgeon to H.M.S. Terror, shows a modification of the molar 

 teeth, which would give it a better claim to subgeneric distinc- 

 tion than the Sten. Weddellii has been supposed to possess*. The 

 three anterior molars on each side of both jaws are four-lobed, 

 two smaller lobes being situated behind the principal lobe and 

 one in front of it ; the remaining molars — two on each side of 

 both jaws — are five-lobed, the principal lobe having one smaller 

 lobe in front and three behind it. The lobes are separated by 

 nearly as deep notches as in the Stenorhynchus leptonyx, but their 

 summits are obtuse. 



* The Sten. Weddellii is the type of the subgenus Leptonyx of ^f. Gray. 



