34 SUMMARY OF CURRENT RESEARCHES RELATING TO 



Fish Vertebrae as Prehistoric Amulets.* — Angelo Mosso gives an 

 account of prehistoric amulets (in the museum of the island Virginia in 

 Lake Varese) which consist of the vertebra? of the pike and of a shark. 



Nervous Lobe of the Hypophysis and the Vascular Sac.§--L. 

 Gentes points out that the vascular sac or infundibular gland is inde- 

 pendent of the nervous lobe of the hypophysis. They are adjacent 

 dependencies of the wall of the infundibulum, but they are not homo- 

 logous. They co-exist in most Teleosteans, but in Selachians the 

 infundibular gland is seen isolated, and in most Vertebrates above fishes 

 the nervous lobe is seen isolated. In Cyclostomes both are absent. 



Tunicata. 



Gill-slit Formation in Ascidians.J — Paul Fechner describes this 

 in Ecteinascidia, Styelopsis, Polycyclus, and Pyrosoma. There appear 

 to be two modes of development in Ascidians. In one the new spiracula 

 (Kiemenspalten) arise throughout independently of those already present. 

 In the other the definite spiracula descend from a few primary slits, 

 from which they arise by division and splitting. After a stage with 

 two pairs of stigmata, there occurs a quickly passing stage with three 

 pairs (which in the later literature are characterised as primary proto- 

 stigmata), and which become very long cross slits, taking up the whole 

 breadth of the pharynx. From the division of each of the primary 

 protostigmata there arise six transverse slits ■ — the secondary proto- 

 stigmata (primary stigmata of van Beneden). By repeated division 

 perpendicular to their length the six first transverse rows of slits arise, 

 each having 12 to 18 spiracula. 



Ascidians of Californian Coast. § — W. E. Ritter gives an account 

 of the off-shore Ascidians of the Californian region. Fourteen species 

 are described ; the depths, geographical position, and other data as to 

 habitat are given. Of 263 stations occupied by the ' Albatross ' from 

 March to June, 1904, only 16 yielded Ascidians. The data obtained 

 are rather scanty to admit of generalisations, but indications in two 

 directions are rather strong. The off-shore Ascidian fauna is consider- 

 ably richer south than north of Point Conception, so far as concerns 

 the areas worked over, and the deep water along and just beyond the 

 continental shelf is more prolific of this form of animal life than is the 

 shallower in-shore water. Twelve of the species described are new. 



Homologies of the Muscles of Cyclosalpa.[| — W. K. Brooks com- 

 municates a note on the musculature of this sub-genus of Salpa. While 

 there is much specialisation among the muscles of the various species, 

 there is a very complete series joining the simplest and least specialised 

 form, the solitary S. pinnata, to the most specialised one, the aggregated 



* Atti R. Accad. Sci. Torino, xlii. (1907) pp. 1162-5 (1 pi.). 



t C.R. Soc. Biol. Paris, lxii. (1907) pp. 499-501. 



% Zeitschr. Wiss. Zool., Ixxxvi. (1907) pp. 523-56 (2 pis. and 2 figs.). 



§ Univ. California Publications, iv. No. 1 (1907) pp. 1-52 (3 pis.). 



|| Johns Hopkins Univ. Circular, No. 3 (1907) pp. 173-4. 



