Mysiclacea, Tanaidacea and Isopoda. ' 407 
The collections from the Tale-Sap are small and include the following 
species : — 
Marine. 
Rhopalophthalmus cgrcgius, Hansen. 
Frp:sh to Brackish Water. 
Nanomysis siamcnsis, gen. and sp. nov. 
Apscudes sp. 
Ligia exotica Roux. 
The Mysid Niuiomysis siamensis affords the only real evidence of the affinities of 
the brackish water fauna of this lake. 
It is closely related to a species I have described from similar habitats in India 
{Potamomysis assimilis, W.M.T.) and shows no kind of relationship with the species 
found in China and Japan. 
Four species have been described as new to science, 
Nanomysis siamensis, gen. et sp. nov. 
Caecidothea kawamiiyai , sp. nov. 
Exosphaeroma chinensis, sp. nov. 
Cleantis annandalei, sp. nov. 
I desire to express my thanks to my wife for the drawings illustrating this 
paper. 
Order MYSIDACEA. 
Sub-order MYSIDA. 
Family MYSIDAE. 
Sub-fam. SIRIELLINAE. 
Genus Siriella, Dana. / 
Siriclla watasci, Nakazawa. 
5. watasci, Nakazawn, 1910, p. 256. pi. viii, figs. 8, 36. 
Locality : — •Tate5^ama, mouth of Tokyo Bay, Japan, two females (presented by 
Dr. Nakazawa). 
In the absence of males, these specimens agree very closely with the description 
given by Nakazawa. The species is only known as yet from Japanese waters. 
Sub-fam. GASTROSACCINAE. 
Genus Gastrosaccus, Norman. 
Gastrosaccus vulgaris, Nakazawa. 
G. vulgaris,- Nakazawa, 1910, p. 253, pi. viii, figs. 6, 23, 24, 29, 35. 
G. vuigaris, Zimiiier, igi8, p. 15 text figs. 1-4. 
Locality : — Osaka Market, Japan, 24. xi, 15, one male. 
Zimmer has completed the description of this species by an account, with 
figures of the first two and last two pleopods of the male. He notes that, in the 
