260 Transactions. — Zoology. 



pneumostome it forms several branches, and the latter, with 

 their accompanying afferent vessels, are fairly well indicated. 

 The vessels on the rectal side of the lung are minute and very 

 much branched, while on the cardiac side only a few traces 

 may be seen. 



The pedal gland opens between the head and foot imme- 

 diately below the mouth ; it forms a long flattish structure, 

 much folded and lying on the floor of the body cavity. Its 

 posterior end is slightly enlai-ged, and enclosed in a cavity in 

 the foot, to which it has a muscular attachment. From the 

 termination of the gland the usual tube or duct proceeds 

 through the substance of the foot, but does not form a caudal 

 mucous pore. 



The retractor muscles : The buccal mass and pedal re- 

 tractors are fused together posteriorly where they unite with 

 the columella of the shell. The buccal retractor rests dor- 

 sally on the pedal muscles, and forms a broad powerful 

 band. The pedal retractors are continuously attached to 

 the foot, and there are no free progressively attached pedal 

 retractors as in Helix. The ocular retractors branch from 

 the pedal muscles ; they bifurcate towards their anterior ends, 

 and supply the inferior tentacle retractors. 



The genital system is particularly interesting, and differs 

 from the three anatomically known species — viz., P. hoch- 

 stetteri, Pfr.,* P. edwardi, Suter,f and P. umula, Pfr.,| in 

 the extreme reduction of the male organs and the absence 

 of a receptaculum seminis ; but, when compared with the 

 genital organs of Schizoglossa novoseelandica, Pfr.,§ a slug- 

 like animal, there is a most remarkable resemblance. Fig. 4 

 gives a general outline of the genitalia. 



There is a blunt, somewhat triangular, projection of the 

 vaginal wall, with a retractor muscle proceeding to the ad- 

 joining body-wall ; this is the only evidence of the male 

 organs before any of the surrounding tissue has been dis- 

 sected away. On removing this outer tissue a small loop 

 is seen to project from the vaginal wall (fig. 5, £>.). This 

 I regard as the posterior termination of the penis, which 

 passes into the vas deferens without any perceptible change, 

 except a slight diminution of the tube. To follow the course 



* Godwin-Austen, Proc. Malac. Soc. London, vol. i., pp. 5-9, pi. i. 

 (by an evident slip of the pen this plate is made to appear as illustrating 

 the anatomy of P. busbyi) ; Collinge, Ann. Mag. N.H., ser. 7, vol. vii., 

 pp. 68-70, pi. ii., figs. 17-21 ; Beutler, Zool. Jahrb. (Abth. f. Morph.), 

 1901, bd. 14, pp. 369-416, t. 26-29. 



t Collinge, ibid., pp. 70-71, pi. ii., figs 22-25. 



J A note on the anatomy of this species has been forwarded to the 

 Malac. Soc. London, but the publication has not yet reached me. 



§ Hedley, Proc. Linn. Soc. N.S.W. (series 2), vol. vii., pp. 387-392, 

 pis. ix.-x. ; Collinge, ibid., pp. 71-72, pi. ii., figs. 26-30. 



