346 OX A COLLECTION OF ECHIURIDS, WITH AN ATTEMPT TO 



Nephridia, two pairs, with spirally coiled internal openings. 



Anal trees, long, brown, pointed anteriorly- They bear short branching outgrowths. 



Locality. Lanzarote, Canary Islands, among lava blocks and stones. Bahia 

 7 — 20 faths. Christmas Island. Indian Ocean, and at Lifu, Loyalty Islands. 



Species 12. Thalassema caudex. Lampert. 



Lampert. Zeitschr. wiss. Zool. Vol. xxxix. 1883, p. 340. 

 Shipley. P. Zool. Soc. London, 189S, p. 472. 



Length of body very various from 5 — 7 cm. Length of proboscis, 1-8 — 2-5 cm. in the 

 preserved specimens. 



Colour, leather-brown or olive-green in spirit specimens. In the fresh state the 

 animal is green with red longitudinal stripes and white spots or papillae. 



Papillae, on the raised longitudinal ridges which correspond with the longitudinal 

 muscles. They are very numerous and arranged in plaques posteriorly. Skin tough. 



Longitudinal muscles, 16 — IS bundles. 



Nephridia, three pairs, with spirally twisted internal opening. The anterior pair 

 open in front of the ventral hooks 1 . 



Anal trees, two long brown tubes. 



Locality. Red Sea, Indian Ocean, Rotuma. At the latter place the specimens 

 were found under growing coral near the edge of the Reef. 



Species 13. Thalassema diapkanes. Sluiter. Plate XXXIII. Fig. 2. 



Sluiter. Natuwrk. Tijdschr. Nederl. Ind. Vol. xlyiii. 1888, p. 244. 



Length of body, 3 cm. Length of proboscis, 3 cm. The proboscis forms a tube just 

 before it joins the body and, in Sluiter's specimens but not in mine, the tip of the 

 proboscis is broad and sharply truncated. 



The skin is very thin and transparent. The papillae are little white specks scattered 

 over the body, but rather more concentrated at the two poles. 



Longitudinal muscles, continuous. 



Nephridia, one pair, without spiral internal openings. 



Anal trees, small, only 5 mm. long, transparent as glass. 



The contents of the alimentary canal are aggregated in pellets, like those I found 

 in Th. kokotoniense. 



Locality. Taken from the mud bottom of the Bay of Batavia at a depth of 

 10 — 12 fathoms. The animals live well in aquaria, hiding their bodies in the mud and 

 stretching out their proboscis into the water. Also from Pigeon Isle, New Britain. 



1 Lampert states this ; I thought that in my specimens the anterior nephridia opened at the level or just 

 behind the level of the ventral hooks. 



