ZOOLOGY AND BOTANY, MIOEOSCOPY, ETC. 733 



M. Delage points to the existence of a series of intermediate forms, 

 and " moreover, and this is the important fact, the heart ought to be 

 considered as a portion of a long dorsal vessel, which has become 

 contractile at one point. The fact that that point is found in the 

 superior, median, or inferior portion of the vessel is, then, an alto- 

 gether secondary fact." Next, the origin of the pericardium by the 

 fusion of pericardiac lacunse is pointed out. The writer explains the 

 difference in the mode of termination of the hearts of these groups, 

 the Isopods having below a cul-de-sac, while the Amphipods have the 

 inferior extremity continued into an azygos inferior aorta, by urging 

 that the fact of the inferior aorta of the Isopoda arising on the 

 anterior face of the heart authorizes us in considering all that portion 

 of the heart below this point as a kind of cul-de-sac, a physiological 

 aneurism developed on the dorsal face. The important differences 

 in the two systems appear to be two : (1) the presence or absence of 

 afferent arteries for the limbs, and (2) the opposite direction taken 

 by the blood current in one as compared with the other. The author, 

 however, believes that the second difference is a result of the first, 

 and that would appear to be due to the special development of part of 

 the centripetal venous system, and by the further development of 

 special vessels out of the ventral sinus. 



After dealing briefly with the Lcemodipoda M. Delage passes to 

 the Tanaida, which he regards as distinct from the rest of the 

 Isopoda ; he points out the characters in which they resemble other 

 groups, and gives a kind of phylogenetic diagram in which they 

 occupy the base of a stem which diverges not only into the three 

 divisions of the Hedriopliihalmata^hut also bears the PodojyJdhalraata ; 

 and the paper concludes with a catalogue of all the species of these 

 two divisions which have been found at Eoscoff. 



Studies on the Bopyridse.* — Professor E. Kossmann describes the 

 genus Gigantione from the Mauritius, and Bopyrina from Naples, and 

 enters into a full account, critical and descriptive, of the characters 

 of these two forms. 



Characters of the Copepoda.| — In this essay Professor Claus 

 especially deals with the Copepods of the Bay of Trieste. In the first 

 half he deals with some anatomical points. He points out that in the 

 heart the lateral clefts always belong to the hinder half and lie in the 

 second thoracic segment ; the cardiac tube is attached to the dorsal 

 integument and to the neighbouring organs by suspensory pieces of 

 connective tissue, which either form separate fibrous bands or com- 

 pound broader plates ; they aid in bounding off the large blood-sinus. 

 The arrangements appear to be simplest in Cetochilus, in which 

 genus the anterior aorta is replaced by a wide blood-lacuna ; the 

 heart of C. septentrionalis is mentioned as a peculiarly good object for 

 investigation. The unusually long cardiac tube has an upper and a 

 lower suspensory ligament, and other attaching fibres, the aiTange- 



* Zeitschr. f. wiss. ZooL, xxsv. (1881) pp. 652-80 (2 pis.), 

 t Glaus' Arbeiten, iii. (1881) pp. 313-32 (3 pis.). 



Ser. 2.— Vol. I. 3 C 



