ZOOLOGY AND BOTANY, MICBOSCOPY^ ETC. 433 



remarkable new species represents a new genus of Pennatulidse, and 

 is named Benthojjtilhim sertum gen. et sp. nov. It was taken in 

 991-1073 fath., thus offering a remarkable exception to Kolliker's 

 generalization that only simpler forms occur in deep water, the new 

 genus being a very highly organized and specialized form of large 

 size, with comples lateral groups of very large polyps. As other 

 forms were also dredged at great depths the generalization will pro- 

 bably be found to rest on very insufficient evidence. 



A peculiar new species of Epizoanthus (E. abyssorum Y.) was taken 

 in 1555-2033 fath. It usually formed the covering of a hermit-crab 

 (Parapagurus pilosimanus). Eight new starfish are also described. 



Fauna of the Pieces of Water of the Riesengebirge.* — Dr. O. 



Zacharias first discusses the fauna of the so-called " Grosser Teich," 

 which lies 1218 metres above the sea, and is 1756 (Paris) feet long 

 by 200 to 560 wide; Daphiia longispina was found to be a very 

 common crustacean, and is of special interest, as it is very common 

 in brackish waters. There were thousands of Polyphemus pediculus, 

 and contrary to expectation, among these males were discovered ; the 

 bluish pigment of this form, which Leydig thought to be placed in 

 the matrix of the cuticle, is rather due to a fluid which is contained 

 in vesicles of connective tissue. The distribution of this species is 

 very carefully detailed. Only one example of the Turbellarian 

 Stenostomum leucops was detected, but the author was able to confirm 

 the statement (made by Leuckart in 1854, but since frequently 

 denied) that there is a distinct orifice at the anterior end of the 

 body ; further observations on this form are promised in a special essay. 



The " Kleiner Teich " is 50 metres lower than the larger piece of 

 water ; its entomostracan fauna was found, with the exception of Poly- 

 phemus pediculus, to be identical with that of the larger lake ; but no 

 direct communication between the two pieces of water was to be made 

 out. The rare Turbellarian Mesostomum viridatum was found in 

 comparative abundance ; M. rostratum was also found ; this form is 

 remarkable for its tactile proboscis, which is extraordinarily sen- 

 sitive ; its contractile power is due to the possession of five bundles 

 of retractor muscles ; its transparency enables the observer to study 

 easily the distribution of its rhabdites ; these are arranged in two 

 rows ; the red-coloured eyes have a very convexly curved lens. 



The author discusses the natural history of these lakes from the 

 geological point of view. 



Minute Fauna of Reservoirs-t — Mr. E. Potts, referring to the diffi- 

 culty of studying deep-water organisms while surrounded by their 

 natural conditions, urges that advantage should be taken of such 

 opportunities as are afforded by the temporary drainage of reservoirs, 

 canals, &c. During a recent drawing off of the water from the Fairmount 

 reservoirs, he availed himself of the opportunity of making such a 

 study. 



Of the fresh-water sponges Spongilla fragilis, Meyenia fluviatilis, 



* Zeitschr. f. Wiss. Zoo!., xli. (1885) pp. 483-516 (1 pi.), 

 t Proc. Acad. Nat. Sci. Philad., 1884, pp. 217-9. 

 Ser. 2.— Vol. V. 2 F 



