814 SUMMARY OF CURRENT RESEARCHES RELATING TO 



off of portions of the sea, which subsequently became fresh water ; 

 parallel instances are Mysis relicta of the Scandinavian lakes, and 

 Spliseroma fossM'um in Italy. 



Action of Sodium Chloride on Cercarise.* — M. E. Perroncito has 

 conducted a number of experiments upon the vitality of Cercariae and 

 encysted larvae from Lymnsea palustris ; he discovered that a solution 

 of salt of even • 65 per cent, was sufficient to destroy these creatures, 

 though the time necessary to effect their destruction was naturally 

 longer in proportion to the weakness of the solution ; desiccation was 

 also absolutely fatal. These facts are clearly of importance, not 

 merely from a scientific but from an economical point of view. Simple 

 drainage, combined with the use of salt, is sufficient to free pasturage 

 from the larval parasites. 



New Species of Myzostoma.f — Prof. L. v. Graff describes a new 

 species of Myzostoma (Jlf. cirripediwni) found attached to Metacrinus 

 rotundus. Its external form resembles that of M. Wyville-Thomsoni 

 Graff. 



Pelagic and Fresh-water Rotatoria.^ — Dr. 0. E. Imhof records 

 the presence of several marine rotifers from the deep waters of the 

 Swiss lakes. In an earlier communication Anursea spinosa and A. longi' 

 spina were mentioned as occurring in the deep water of lakes ; these 

 have been stated by Crisp not to be new species, but severally identical 

 with A. longispina Kellicott and A. coclilearis Gosse, and Zacharias 

 has further confirmed this opinion that A. longispina = A. cocMearis ; 

 a closer examination has convinced Imhof that the species are distinct, 

 as are also A. spinosa and A. longispina. A. tuherosa, a new form, is 

 recorded from the Eibsee, in Bavaria, and A. intermedia from the 

 Staffelsee. The Konigsee is inhabited by another marine form, 

 A. aculeata var. regalis. The following marine species are also recorded 

 from various lakes : Triarthra longiseta, Polyarthra platyptera, Syn~ 

 chseta pectinata, Monocerca cornuta, Euchlanis sp., Motommata tigris, 

 Philodina aculeata, EucJilanis lynceus, Motif er sp., Colurus caudatus. 



Echinoderir) ata. 



Vascular System of Echinoids.§ — Dr. P. Herbert Carpenter 

 discusses the answer recently given by Kochler to his criticisms on 

 that author's account of the vascular system of Echinoids ; Carpenter 

 still doubts the accuracy of Prof. Perrier's statements as to the rela- 

 tion of the " ovoid gland " with the exterior, basing his objections on 

 the theoretical ground that there should be similarity of structure 

 among Echinoderms, and that the water-vascular and blood-vascular 

 systems of Asterids have been shown to be fundamentally independent 

 of each other ; and on the practical ground that investigations by 

 means of injections are not so likely to be trustworthy as those made 

 on sections ; the French observers have used the former, Ludwig the 



* Arch. Ital. de Biol., vi. (1884) pp. 154-6. 



t Tran?. Linn. Soc. Lond. (Zool.), ii. (1885) pp. 444-6 (1 fig. of a pi.). 



i Zool. Anzeig., viii. (1885) pp. 322-5. 



§ Quart. Jour. Micr. Sci.— Suppl., 1885, pp. 139-55. 



