322 siGNOR F. s. MONTiCELLi ON [June 4, 



for this Distomum, which up to now has been found in the stomach 

 only. 



D, microcephiilum, Eaird (Cat. Ent. Brit. Mus. p. 98, pi. ii. fig. 2), 

 from the stomach of Acanthias vulgaris, is, I think, based on small 

 specimens of D. veliporum. 



3. Distomum microporum, sp. n. (Plate XXXIII. fig. 1.) 



Body elongated, pyriform, of a yellow colour, finely plicated 

 transversely, with a small caudal appendage ; in front very narrow 

 aud cylindrical, behind gradually enlarged and swollen ; posterior 

 extremity obtusely lanceolate. Anterior sucker large, circular, sub- 

 terminal, situated entirely on the ventral surface ; posterior sucker 

 smaller than the anterior, circular, placed at the commencement of 

 the posterior enlargement of the body. The small genital antrum is 

 placed almost immediately behind the anterior sucker. Penis of 

 moderate size, enlarged at the base. Excretory system opening at 

 the extremity of body subdorsally. Lengths of the specimens 20- 

 32 millim. 



The six specimens of this new species were taken by Dr. Giinther 

 from a Playyodns ferox from Madeira. Trematoda have not been 

 previously observed in the Ptagyodontina. 



4. Distomum gigas, Nardo, Mem. sopra alcune nuove e rare 

 specie di Entozoi, in Ht usinger's Zeitsch. f. org. Physik, 1827, p. C8. 

 (Plate XXXIII. figs. 2, 3.) 



I give a figure of tiiis rare species, which, so far as I know, has not 

 yet been figured. The only specimen existing in the collection was 

 taken from the stomach of an Ausonia cuvieri which was found on 

 the British coast. 



5. Distomum halosauri, Jeffrev Bell, Ann. & Mag. Nat. Hist. 

 (5) xix. pp. llG-117. (Plate XXXIII. figs. 4, 5.) 



Mr. Bell has described this species, found in the enlarged ends of 

 the ureters of a Hulosaurus macrochir dredged off Cape St. Vincent. 

 I give a figure of this interesting species, and I add some remarks to 

 Bell's description. 



Anterior sucker small, globose, situated ventrally, presenting in 

 front a pointed elevation, vvliich, observed in a microscopical pre- 

 paration, seems to be pierced by a cavity (see fig. .5). Posterior 

 sucker as large or hardly larger than the anterior, circular, enlarged, 

 prominent. Pharynx enclosed in the anterior sucker ; oesoj>hagus 

 slender ; intestinal caeca not very long. Testes in irregular outline ; 

 ovarium before the testes ; uterus much extended through the 

 body ; genital antrum placed immediately before the posterior sucker. 



Entozoa have not been before discovered in Halosaurus. 



6. Didymozoon serrani, sp. n. (Plate XXXIII. fig. 6.) 



This new species was found on the gills of a Serranus fimbriatus 

 from Madeira ; the same undescril)ed species I have frequently found 

 attached to the gills of the Serranus gigas of the Gulf of Naples. 



