72 



Sericogaster fasciatus. Ser. niger ; scutello, antennis, pedibus- 

 que rufescentibus ; femoribus posticis ad basin apiceque antenna- 

 rum piceis ; abdominis segmentis Jlavo irregulariter marginatis. 



Long. corp. lin. 44. Exp. alar, lin, 64. 



Hab. in Nov^ Hollandia. — In Mus. Dom. Hope. 



Genus Dorylus, Fabr. 



DoRYLUs Orientalis. a Dor. helvolo distinguihir, staturd paidlo 

 graciliore, nervo recurrenti alarum anticarum jione medium 

 areolce submarginalis inserto, nervisque bints internis (posti- 

 carum) nervis duobus transversis C07inexis. 



Hab. in India Orientali. — In Mus. Westw. Communicavit Dom. 

 W. W. Saunders, F.L.S. 



Mr. Owen read a paper " On the Anatomy of Distoma clavatum, 

 Rud.," an Entozoon of an intermediate grade of structure between 

 the two subjects, Trichina and Linguatula, which he has recently 

 brought under the notice of the Society : the one manifesting simply 

 a homogeneous granular pulp enveloped in a transparent, thin, elastic 

 tegument ; and the other having distinctly developed nervous ganglia 

 and filaments, a muscular tunic, a digestive canal contained in an 

 abdominal cavity, ovaries, oviduct, and fecundating glands. 



The specimen of Dist. clavatum examined by Mr. Owen measured 

 2 inches and 2 lines in length, and 1-}- inch in circumference at its 

 thickest part. Its outer integument was thin, crisp, and semitrans- 

 parent ; transversely and minutely wrinkled, and evidently fibrous 

 in the same direction ; and adhering but slightly, at least after ma- 

 ceration in spirit, to the succeeding layer. This latter tunic was 

 evidently muscular, and was composed of longitudinal fibres : it ad- 

 hered pretty closely to the membrane immediately inclosing the cel- 

 lular parenchyma of the body, but was separable from it by careful 

 manipulation. The muscular tunic was beautifully ornamented by 

 tortuous vessels containing a dark-coloured fluid. 



The anterior orifice is surrounded by a muscular sphincter, forming 

 a suctorious disc, at the bottom of which is a minute orifice leading 

 to the digestive tubes. These are two in number, and are continued, 

 slightly enlarging and diverging from one another, to the cells at 

 the posterior part of the body. 



The large cup-like canity, about 3 lines posterior to the anterior 

 end of the animal, is simply for adhesion, and has no communication 

 with the interior of the body ; but immediately in front of it is a 

 small transverse slit, concealed by the wrinkles of the integument, 

 which forms the outlet of the generative organs. 



At the posterior extremity of the body there is a minute central 

 orifice, leading into a narrow cavity formed between two layers of a 



