100 



MR W. E. HOYLE ON 



EXPLANATION OF THE PLATES.* 



Explanation of Reference Letters the same in both Plates. 



a.g, accessory gland ; a.g', duct of same. 



a.n.c, anterior nervous commissure. 



c.s, cirrus sac. 



cu, cuticle. 



c.z, " Chitinzapfen." 



ep, epidermis. 



g.o, genital openings. 



h.g, hook -gland ; h.g', duct of same. 



i, intestine. 



me, mesentery. 



ml, longitudinal muscles. 



m.o, oblique muscles. 



m.t, transverse muscles. 



n, nerves. 



n.g, nerve ganglion. 



nu, nucleus of sarcolemtna. 



ce, oesophagus. 



o.d, oviduct. 



o.p, oral papilla. 



ov, ovary. 



par, subepidermic cellular layer. 



p.c, parietal cells. 



r.s, receptaculum seminis. 



s.c, stigmatic cells. 



t, testis. 



v, vagina. 



v.d, vas deferens ; v.d', ccecal portion of same. 



v.s, vesicula seminalis. 



u.e, extensor unci muscle. 



u.f flexor unci muscle. 



u.f.a, flexor accessorius unci muscle. 



u.r, retractor unci muscle. 



u.b.a, adductor basis unci muscle. 



u.b.p, protractor basis unci muscle. 



Fig. 



1.- 



Fig. 



2- 



Fig. 



3.- 



Fig. 



4.- 



Fig. 



5.- 



Fig. 



6.- 



Fig. 



7.- 



Fig. 



8.- 



Fig. 



9.- 



Fig. 



10.- 



Fig. 



11.- 



Fig. 



12.- 



Fig. 



13. - 



Fig. 



14.- 



Fig. 



15.- 



Fig. 



10.- 



Fig. 



17.- 



Plate XXVIT. 

 Muscles, Digestive and Seceetory Okgans. 



View of Pentastomum protelis, ventral surface (small male specimen). 



Surface view of the cuticle. 



Hooks : I, lateral ; m, median. 



Side view of oral papilla. 

 —Transverse section of intestine and mesenteries, with posterior portion of testis. 



Transverse sections of oesophagus. 



■Transverse section of rectum. 



•Median longitudinal section of head. 



Transverse section of body-wall. 



•Transverse section of body, posterior to union of vas deferens and vesicula seminalis. 



•Stigmatic cells. 



Muscles of hook. 

 —Transverse section near the posterior extremity. 

 —View of transverse muscles. 



Large glandular cells from the body-wall. 

 —Terminations of muscular fibres in the cuticle. 



Arrangement of muscles are seen from within the body-cavity. 



* The drawings were (<<y the most pail made by the aid of the camera with Zeiss' microscope. The 

 magnifying power employed is marked on the plate beside every drawing. 



