582 SUMJr.VRY OF CTJIIRENT RESEAKCIIES RELATING TO 



tlio gastric secretion of L. ruhcUiis and A. mncnm appears to act better 

 iu the pnscucc of weak acids tlnvii in that of alkalies. The cells of the 

 typblosolo not only servo in absorption, but have a digestive function 

 Biniilar to tliat of tlie pancreas in Vertebrates. 



L. ruhtUus and A. fcetida are found as far north as the mouth of the 

 Lena. In Siberia there is A. tenuis, wliich has, as yet, only been found 

 iu North America and Scandinavia. L. vuiltisjnuus and L. hrcvisphius 

 arc 8yiionyn)s of A. mucosa. In the Caucasus, the new species L. cancn- 

 sicus, Dcndrohscna Bogdauou-ii, and D. Nassonoicii have been found, in 

 addition to A. arhorea, A. profuga, A. louga, and A. siihrubicun(Ja, which 

 have also been found in the Crimea tind in South Eussia. In Central 

 Eussia, A. mucosa, A. carnea, A. 'pellucida, A. fcelida, D. Baicliii, 

 L. rubcllus, and L. agricola have been found. 



New Annelid. Sutroa rostrata.* — "Mr. G. Eiscn describes, under 

 the name of Suiroa roslrata, a new Lumbriculine found near San 

 Francisco. The seminal receptacles consist of several pairs of lobes, 

 vhich all open in the so-called albuminous gland in the eighth segment. 

 A solitary albuminous gland is found in the eighth segment. Presoptal 

 and interseptal secondary dorsal vessels arc branching and feathered. 

 Postseptal vessels are gastric, not feathered, nor branching; spines 

 simple, not forked ; cephalic lobe filiform. The new genus is closely 

 allied to the two known genera of the sub-family Lumbriculina — Lum- 

 hriculus and Bhi/nchehnis. The " albuminous gland," however, difi'ers 

 Eomewhat in structiu-e ; for, instead of being distinctly glandular, it is 

 covered by smooth epithelium, under which are found numerous long 

 and narrow cells. All the six seminal receptacles, moreover, open into 

 the gland instead of having separate pores. The segmental organs are 

 foi;nd in all the segments behind the twelfth, and are very similar to 

 those of Bhijnchelmis. The dorsal vessel differs from that of the other 

 two genera iu not being forked. 



Two new Aquatic Worms from North America.f— Dr. A. C. Stokes 

 points out that very little is yet known as to the oligochaatous worms of 

 Korth America. Acolosoma distichim sp. n. is very abundant in stale, 

 or even partially decayed collections of aquatic plants ; it is about 

 2/5 in. long, but none have yet been seen in the sexually mature stage. 

 The body is colourless, depressed, changeable in form, and attractively 

 variegated by the large, irregular, red spots which are distinctive of the 

 genus. There is a large subcircular lip, the lower surface of which is 

 clothed by fine vibratilc cilia ; laterally and posteriorly to the mouth 

 there is a thick, muscular, U-shaped lip. The nephridial tubes begin 

 with a slightly expanded orifice which is clothed with long, fine cilia ; 

 there is no undulating membrane. The labial cilia are the chiejf 

 swimming organs. Pristina jlavifrons sp. n. has been found abundantly 

 on the under surface of Lemna polyrrhiza, and among the leaflets of 

 MyriophjUum ; the setae on the body are short, widely separated, and 

 there is no invariable rule as to the number of stylets in each fascicle. 

 Kg sexually mature forms have been observed, reproduction being 

 effected by fission. 



* Mem. California Acad. Sci., ii. (1888) pp. 1-8 (2 pis.). 

 t The Microscope, viii. (1888) pp. 33-41 (1 pi.). 



