100 NEW GYEODACTYLOID TEEMATODES FROM AUSTRALIAN PISHES, 



This is especially plain in the specimen figured, where the body' had been 

 accidentally drawn out, the body constriction being in consequence obliterated. 

 The reeeptaculum seminis is rather small. The yolk-reservoir is clearly visible. 

 Found on the gills of Therapon hilli Castelnau, from the Thomson River, 

 at Longi-eacb, Central Queensland. 



13. E ji p L B u B s 31 A, n.gen. 



Small TetraoncJiinae, with strongly developed lateral body regions. Disc 

 not sharply marked off from body, provided with four large and tAvo very small 

 books, as in Baitreosoma. Eyes present. Intestinal limbs communicatLug pos- 

 teriorly and devoid of caeca. Vagina absent, Cin'us a simple elongated tube. 

 Yolk confined to the anterior region of the body. 



Found on the gills of a freshwater fish. 



Type species, E. pyriforme J. & T. 



Ejipledrosoma pyriforme, n.sp. (Plate xiv., fig. 31; xv., fig-s. 32-34.) 



This is a small parasite, about .37 mm. in lengih, and .11 mm. in gi-eatest 

 breadth, with broadly expanded sides and rather thick body. 



The disc, which is not sharply marked off from the body of the worm, is 

 provided with two pairs of large hooks, viz., a posterior ventral pair, the bases 

 of wlii-ch are joined by a short transverse cliitinous bar; and a more anterior, 

 laterally directed pair, each of which is ankylosed at its base with an inwardly 

 and posteriorly directed chitin-bar. These large hooks are all slightly biramous 

 at their bases. Laterally the clasping disc possesses two small lobes each beai-- 

 ing a small hook, as in Baitreosoma. The large posterior hooks also articulate 

 at their bases each with a very minute chitin-piece. To these chitin-pieces the 

 musculature of the hooks is attached. 



Four ventral longitudinal muscles supply the disc; an outer pair serving 

 the more anterior pair of hooks, and a median pair inserted into the small 

 chitin-pieces articulating with the posterior hooks. A transverse muscle uniting 

 these basal pieces is also present. 



The body-wall is thick and devoid of epidermal papillae. The circular 

 muscle-layer is strongly marked; while the inner (longitudinal) series is pro- 

 minent ventrally but could not be detected dorsally and laterally. In the pos- 

 terior half of the animal the ventral longitudinal muscles are highly developed 

 to foi-m the four longitudinal muscles supplying the disc, as already described. 

 These muscle-layers separating the several organs from the intestine are pro- 

 minent in the anterior region of the animal. The body parenchyma in the 

 posterior narrow portion of the worm is curiously developed, giving it a 

 "peculiar globular appearance, somewhat similar to that seen in Baitreosoma. 

 There are four pairs of prominent head-organs on either side, the glands which 

 supply them lying laterally to the phar;\'nx. On either side of the pharynx ai-e 

 two pairs of remarkable glands which open on the body surface, ventrally, close 

 to the cirrus; it is possible that they possess a copulatory function. 



The mouth opens ventrally. The large, almost spherical pharynx is followed 

 by a very short oesophagTis. The two limbs of the intestine unite behind and 

 are devoid of caeca. The intestinal walls are of remarkable thickness, but con- 

 sist, nevertheless, of only a single layer of narrow columnar and vei-y vacuolated 

 cells, resting on a prominent basal membrane. 



Neither excretory nor central nervous systems could be detected. Two 

 pairs of eyes are present, situated well within the parenchyma, each pair at 



