348 
SUMMARY OF CURRENT RESEARCHES RELATING TO 
gut, into tlie lumen, into which they open. As there are anal nephridia 
in the Gephyrea and as many Arthropods are provided with gut-tubes — 
the Malpighian tubules— this discovery is of interest, and may prove to 
throw light on the origin of these last, which have, indeed, been already 
compared to nephridia. 
Aquatic Earthworms.* — Mr. F. E. Beddard remarks that Allurus 
tetraedrus is not the only “ earthworm ” that has been found in water. 
Two freshwater species of AcantJiodrilus have been found in the Falkland 
Islands. 
Perichaeta indica.f — Mr. R. Service has a note on the occurrence 
of this exotic species in hot-houses ; he thinks an extensive search would 
show tiiat it is of general distribution in British hot-houses kept at a 
high temperature. 
Development of Vascular System in Annelids.^ — Dr. F. Vejdovsky 
discusses this subject with special reference to embryos of Allolobojphora 
foetida, All. jputra , All. trajpezoides , and Bhynchelniis, of which figures are 
given. The whole paper is, unfortunately, in Bohemian. 
Phymosoma.§ — Mr. A. E. Shipley, while describing a new species of 
Phymosoma , takes the opportunity of giving a synopsis of the genus and 
some account of its geographical distribution. P. Weldoni sp. n. is from 
Bimini Island, the Bahamas ; the tentacles, of which there are from 
seventy to ninety, are distinguished from those of P. varians by the 
absence of the rows of skeletal cells which form so interesting a feature 
of the latter species. Their place is occupied by a well-developed fibrous 
connective tissue, which passes down into the base of the lophophore 
and is there continuous with the connective tissue which surrounds the 
oesophagus, and which serves as a point of attachment to the retractor 
.muscles. The absence of hooks on the introvert is a marked feature of 
this new species. The blood-reservoir is much larger and the heart 
longer than in P. varians , and the latter organ becomes involved in the 
twisting of the alimentary canal, while its capacity is much increased 
by a number of small diverticula, which project as finger-like processes. 
The blood-corpuscles are either large clear cells with well- developed 
outlines, a well-stained nucleus and, apparently, no cell-contents, or 
smaller bodies with a protoplasmic body w'hich stains well and a central 
nucleus. 
The genus is divided into species that (I.) are without and (II.) have 
hooks ; of the former four have four retractors and one (P. Weldoni ) 
tw r o ; of the latter one has two, one three, and the rest (19) four 
retractors. 
With regard to their geographical distribution, the existing body of 
evidence points to the Malay Archipelago as the head-quarters of the 
genus ; with but few exceptions, it is only found in tropical seas, and 
the species have a preference for shallow waters. These latter facts 
may be explained by the fact that the animals only flourish in com- 
paratively warm water. These conditions of temperature may be the 
* Quart. Journ. Micr. Sci., xxxi. (1890) pp. 208-10. f T. c., pp. 390-8. 
t SB. K. Bohm. Gesell. Wise., ii. (1890) pp. 155-64 (1 pi.). 
§ Quart. Journ. Micr. Sci., xxxii. (1891) pp. 111-26 (1 pi.). 
