436 SUMMARY OF CURRENT RESEARCHES RELATING TO 



Knowsley Park, Lanes. The body is elongated and narrow ; the face 

 long and prone, and has a projecting hook anteriorly with two red 

 frontal eyes ; the toes are long and blade-shaped. Two very good 

 figures accompany the text. Size 240 fi. 



A. Seligo * describes Tubicolaria natans sp. n., which is really a 

 Conochilus, resembling G. dossuarius in its habits. It was found in the 

 lakes of Stuhm in East Prussia, is free swimming, without tube, occurs 

 singly, and does not form colonies, but carries 1-3 eggs attached to 

 the posterior end. It has two long ventral antennaB, which are separate 

 to their base. Size 140-200 /a. 



Max Voigt f describes Anursea aculeata var. divergens, a new variety 

 with rather long anterior and posterior spines. 



Echinoderma. 



Calcareous Plates of Synapta and Ankyroderma.+ — Ed. Herouard 

 expounds the theory that the anchor-plate of Synapta is derived from a 

 theoretical hexagonal honeycomb. Some interesting abnormalities are 

 figured in support of the theory. The law is stated that the meshes in 

 the calcareous plates decrease in size in precise relation to the order of 

 their formation. The homology between the plates in Anhyroderma and 

 in Synapta is pointed out. 



Minute Structure of Cuvierian Organs.§ — Ph. Barthels returns 

 to a subject which he discussed in 1896, and points out, in criticism of 

 Russo, that in Molothuria helleri, &c. the wall of the Cuvierian organs 

 always shows the following layers : — internal epithelium, internal con- 

 nective tissue, circular and longitudinal musculature, external connective 

 tissue, and external epithelium. 



New Holothurian from New Zealand. || — A. Reiffen describes Lud- 

 wigia ocnoides g. n. ( = Colochirus ocnoides Dendy). The body is elon- 

 gated and curved, without a ventral sole, with ten tentacles of which 

 the two ventral ones are smaller than the others. There are well- 

 developed tube-feet, with distinct suctorial discs dorsally as well as 

 ventrally on the radii, — but rudimentary towards both ends of the body ; 

 the calcareous bodies (plates, rods, &c.) differ considerably in different 

 regions of the body ; retractors and longitudinal muscles are undivided, 

 except where the latter adjoin the pharynx ; the radialia of the calcare- 

 ous ring consist of one piece, narrow, thin, and brittle ; the interradialia 

 are short and thick ; the elastic membrane of the water vascular system 

 is distinctly recognisable ; the cloaca occupies the whole of the posterior 

 third of the body ; the respiratory trees open separately into the cloaca ; 

 to right and left there is a tuft of unbranched genital tubules, and the 

 opening is on a minute papilla between the two dorsal feelers. 



An abnormal six-rayed specimen is described. A sixth radius and 

 interradius have been interpolated between the right dorsal and right 

 ventral radius, that is, on the right dorsal interradius. 



* Untersuchungen in den Stuhmer Seen, Danzig, 1900, pp. 1-60 (1 fig.). 

 t Beitr. zur Kenntniss des Planktons pomm. Seen, Forschungsberichte Plon, 

 Teil 9 (1902) pp. 72-86 (2 figs.). 



J Bull. Zool. Soc. France, xxvii. (1902) pp. 46-51 (8 figs.). 



§ Zool. Anzeig., xxv. (1902) pp. 392-5. 



|| Zeitschr. wiss. Zoo]., lxix. (1901) pp. 598-621 (1 pi.). 



