Dr. O'Bryen Bellingham on Irish Entozoa. 163 



which it had been previously united ; he likewise removed it from 

 the order Cestoidea to Trematoda, to which it properly belongs. 

 The species are not numerous ; they inhabit the frontal sinus, 

 the lungs or peritonseal cavity, and never occur in the alimentary 

 canal. Hitherto species of this genus have been found only in 

 a few mammalia and reptiles ; they have never been detected in 

 either birds or fish. 

 Pentastoma tanioides*. Frontal sinus of dog (Canis familiaris). 



Order 4. CESTOIDEA. 

 (Derived from Keorbs, cingulum, and eitios, forma.) 



The order Cestoidea is characterized as follows. Body elon- 

 gated, flattened, soft, continuous or articulated. Head very sel- 

 dom provided with simple lips, but in almost all cases furnished 

 with two or four bothrii, depressions or suckers : all the indivi- 

 duals hermaphrodite. 



The Entozoa included in the order Cestoidea do not form a 

 very natural family ; the head differs so much in the several ge- 

 nera ; in some being flattened, pyramidal or tetragonal, with two 

 or four opposite depressions, while in others it is truncate, hemi- 

 spherical or globular, and provided with a proboscis which is 

 often armed with a circle of hook-like processes. The neck is as 

 frequently absent as present. The body is elongated, flat, soft, 

 continuous or articulated, with .marginal or central pores. The 

 species occur in mammalia, birds, reptiles and fish. They inhabit 

 almost exclusively the alimentary canal. 



Genus 14. Scolex. 

 (Derived from (tkwXt)^, vermis.) 

 Gen.Char. — Body flattened, soft and continuous, without any trace of 

 articulation, enlarging into a head anteriorly, posteriorly attenu- 

 ated. Head tetragonal, provided with four ear-shaped depressions. 



This genus was established by Miiller, and has been adopted 



* The Pentastoma ttenioides was named so from its resemblance to 

 the Taenia : it is not a common species ; I possess but a single speci- 

 men. 



It measures upwards of 2^ inches in length, and half an inch in 

 breadth at its widest part. Colour whitish, of a dirty yellow-brown 

 along the median line. Body flattened, anteriorly broad, and dimi- 

 nishing gradually to the posterior extremity ; marked with numerous 

 transverse elevated lines, resembling the joints of the Taenia when 

 contracted ; margin crenate j dorsal surface prominent along the me- 

 dian line. Pores live in number, small, and placed in the form of a 

 half- moon upon the abdominal surface of the anterior extremity. The 

 two lateral pores upon each side of the mouth of an ovate shape, 

 with a little, sharp, hook-like process projecting from each. 



