225 



BkDRTJRIS 8IRBD0NIB (PI. I.N. fig. 1-1). 



Female. Body 13 millimetres long, ', millimetre broad, strongly 

 striated across, narrower at the anterior than the posterior extre- 

 mity, this latter terminating in an obtuse point furnished with what 

 Diesing calls a suctorial papilla, by which it adhered to the coat of 

 the stomach of the Siredon. Male ? 



Hah. Stomach of the Siredon MexieamtS from Mexico. British 

 Museum Collection. 



Along with this interesting species, and in the abdominal cavity 

 of the same animal, were three specimens of another Nematoid Worm 

 of a very different form. I consider it to belong to the family 

 Stronyylidee, and to a genus which Dujardin established under the 

 name of Leptodera, so called from the long narrow neck (Xenri^, 

 //arrow, £ep»j, neck) which distinguishes the species upon which the 

 genus was founded. Only one species of this genus has as yet been 

 described, — the Leptodera flexilis of Dujardin, which was found 

 parasitic in the vas deferens of one of the Common Slugs (Limax 

 cinereus). This species is only from 2£ millimetres (male) to 4 mill, 

 (female) in length, whilst the new species from the Siredon mea- 

 sures from 25 to 16 mill. 



Leptodera elongata (PI. LII. fig. 6-9). 



Female. 25 millimetres long. Body filiform, neck long and 

 slender ; tail terminating in a long sharp point. Vulva situated 

 about the middle of the length of the body. 



Male. 16 millimetres long. Body filiform, neck long and slen- 

 der, tail sharp-pointed. Spicula double, proceeding from a swelling 

 near the commencement of the tail, and accompanied by two short 

 membranous expansions like wings. 



Hah. Abdominal cavity of Siredon Mexicanns. B.M. Collection. 



EXPLANATION OF PLATF. I. II. 



Fig. 1. Jledrurix Siredonix, natural size. 



Fig. 2. Hedruris Siredonix, enlarged. 



Fig. X Head of Hedruris Siredonix, enlarged. 



Fig. 4. Tail of Hedruris Sirrdouis, enlarged. 



Fig. 5. Tail of //. androphora, to ihow die claw. 



Fig. 6. Leptodera elonyata, natural size. 



Fig. 7. J^ejitodera elongata, enlarged. 



Fig. 8. Head and neck of Leptodera elonyala. 



Fig. 9. Tail of Leptodera etmgata, enlarged. 



4. Description of new I'inm;. By Syi.\ \m s 11am. in. 



1. Pinna Carolinensis. P. teata onffiuto-cunei/brmi, $oli- 



diusrulit, d/irarra, suhi iiflul 'n, carina- centralis c.rpertc, nisi 

 maryincm ret 'ralcm ju.i/a undifp/e n, statu : rust is jmucis (''/- 

 citer 7-10), va/idi8, remotis, ro/nndati.x, et st/iianiis brevibus 



No. CCCLXI. — Proceedings oi thi Zoological Society. 



