Zoology. 841 
Only sixteen species are described, ten of which are Nematodes 
and six Cestodes. The species obtained were chiefly from the 
alimentary tract of birds, and include four new forms of Ascaris, 
three of Filaria, one of Prothelmius, four of Tenia, and two o 
Tetrabothrium. The appendix mentions a large larval Echi- 
norhynchus found in the abdomen of a Euphausia, two Distoma, 
and a Gordius found in a crab, so that the other groups of 
Helminths are not entirely absent from the collection. 
Motiusca.—The report upon the Heteropoda of the Challenger 
collection, by E. A. Smith, although short, contains a most complete 
synonymic list of all known forms of the group. It is the fifth 
report in Vol. XXIII. 
The first two memoirs of Vol. XXIII. of the Challenger 
Reports are by Dr. Paul Pelseneer, and treat of the Pteropoda 
Thecosomata, the Gymnosomata having been previously dealt with 
in Vol. XIX. The Thecosomata have a less highly organized 
alimentary canal than the Gymnosomata, and content themselves 
with humbler prey, feeding chiefly on Radiolaria, Foraminifera, 
Infusoria, and even on some of the lower Algw. Specimens of 
the group were taken alive at seventy different stations, but no 
undescribed species were found. All the generic titles that have 
en given may be reduced: to eight, viz. : Limacina, Peraclis, 
Clio, Cuvierina, Cavolinia, Cymbulia, Cymbuliopsis, gen. nov. 
and Gleba. The third part of the report treats of the anatomy of 
the Pteropoda generally. He considers the group, not as a class, 
ut as a recent and specialized variation from the Gastropod type. 
He places them among the Pectinibranchiate Oplsthobranchs, and 
traces the Thecosomata to the Bulloidea, and the Gymnosomata to 
the Aplysioidea. | 
_Crustacra.—Vol. XXIV. of the Challenger Reports is occu- 
pied with the report of C. Spence Bate, F.R.S., on the Crustacea 
Macrura. Though styled one volume, it is in wo goodly 
tomes, the one containing 1030 pages of text, the other 157 litho- 
graphic plates. Not only are generic and specific diagnoses given 
with minuteness, but all that is known of the developmental stages 
(in which direction there is still much work to be _done) is 
reproduced. Bate follows Dana in placing the Penseidea in a sepa- 
rate division, which he names Dendrobranc iata, and he considers the 
izopoda or Stomapoda as forming an aberrant branch of the 
robranchiata, more nearly allied to the degraded forms of the 
Penæidea than to those of any other group. He asserts that, 
with the exception of the pereiopoda, the several genera do not 
possess a single character that is not held in common with some 
genus of the poner divides the Macrura into the two principal 
* 
