ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 43 



pericardium ; (3) that the relations of heart and pericardium are thus 

 similar to those in Tunicates, especially Appendicular ia. 



Bitter has shown that the heart of Balanoglossus occidentalis is the 

 ventral wall of the pericardium pocketed with the pericardial cavity, the 

 mouth of the pocket remaining open backward and laterally, though 

 narrowly, to form the main blood-vessels. In a word, the heart is con- 

 structed on the principle of the Tunicate heart. This type of heart is 

 so unique, that " it is difficult enough to comprehend how it could have 

 arisen once, to say nothing of its having arisen anew tivice." There is 

 evidence here of real affinity between Tunicata and Enteropneusta. 



Movements of Enteropneusta.* — W. E. Ritter has made some 

 interesting observations on the movements of Balanoglossus occidentalis 

 and Dolichoglossus pusillus, from Puget Sound and the Calif ornian coast. 



Movements of both boring and locomotion are effected by a com- 

 bination of ciliary and muscular action. The former is most in evidence 

 when the animal creeps about on the surface of objects ; when boring, 

 -or moving up and down its canal, muscular action is most used. 



"When burrowing, the worm shows on its proboscis contraction-waves 

 that move along from tip to base, but often remaining stationary in the 

 form of great blebs. When in its burrow these blebs act chiefly as 

 holdfasts, by which, through the contraction of the longitudinal muscles 

 of the proboscis and collar, the whole body is drawn forward. The 

 muscles most concerned in this are, first, those of the proboscis ; second, 

 the radio-longitudinal muscles of the collar ; and, third, the longitudinal 

 muscles of the " thorax-abdomen." 



We have, in Enteropneusts, a system of locomotor muscles acting on 

 an axial skeleton, derived in large part from the digestive tract. No- 

 where else in Invertebrates do we find locomotion accomplished by 

 muscles attached either to the intestinal tract or to derivatives of it. 

 This gives an increased importance to the significance of the peculiar 

 muscular relations of the collar region. (Ecology is here, perhaps, of 

 service to morphology. 



Echinoderma. 



New Crinoid.t — R. Koehler and F. A. Bather describe Gephyrocrinus 

 grimaldii g. et sp. n., a new Crinoid dredged by the Prince of Monaco, 

 at a depth of 1786 metres, near Hierre, in the Canaries. It is referred 

 to the Hyocrinidse, a family represented until recently by a single species, 

 Hyocrinus oethellianus, dredged by the 'Challenger.' The specimen 

 differs from Hyocrinus, and from all - known Crinoids, in the fact that 

 the food-grooves are carried across from the fourth brachials to the 

 orals on a thin unplated membrane stretching like the web of a duck's 

 foot between each arm and the tegmen. Minor points of distinction 

 from Hyocrinus, such as the fusion of the basals, the greater thickness 

 of the cup-plates, the almost complete atrophy of the ambulacrids, and 

 the form of the pinnules, have led the authors to give a fresh diagnosis 

 of the Hyocrinidse. 



* Biol. Bull., iii. (1902) pp. 255-61. 



t Mem. Soc. Zool. France, xv. (1902) pp. 68-79 (4 figs.). 



