ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 219 



scattered among these are large brown cells, which are probably glandular. 

 In the posterior dorsal region the hypodermis is modified to form a small 

 sensitive crypt, similar to that which is found in Proneomenia. The body- 

 cavity is occupied by a fundamental connective tissue, similar to that which 

 is found in various molluscs ; below the pedal groove there is a larger 

 sinus, and here the respiratory changes are effected by the currents set in 

 motion by vibratile cilia ; of the circulatory system, the heart alone is well 

 differentiated ; this is surrounded posteriorly by a large pericardium from 

 which two simple nephridial tubes, surrounded by a secreting cellular mass, 

 are given off. An anal cloaca is formed where these tubes unite in the 

 region of the rectum. Though the animal was not sexually mature, it was 

 clear that the generative apparatus was on the type of that of Proneomenia. 

 There is a true radula with eight strong teeth, large salivary glands, and a 

 small dorsal caecum. The brain is large, and the lateral nerves immediately 

 dilate into a small special ganglion ; the two lateral bands are united by a 

 transverse ganglionic commissure, and a strong commissure connects the 

 two anterior pedal ganglia ; no sublingual commissure could be made out. 



* Challenger ' Scaphopoda and Gastropoda.* — The Eev. A. B. Watson 

 has a gigantic report on the Scaphopoda and Gastropoda collected by the 

 ' Challenger '; there are in the collection about 1300 recognizable species, 

 and some 400 indistinguishable furms. At 41 stations, whose depths range 

 from 400 to 2650 fathoms, 89 old, 135 new species, and 46 indistinguishable 

 forms were collected. On the whole, the collection is disappointing, but 

 the methods of more recent dredging show that mechanical improvements may 

 yet be introduced which will greatly extend our knowledge of deep-sea life. 

 The author explains that the classification which he has adopted is not one 

 of which he approves, but is the least objectionable he could find. 



Mr. Watson remains of the opinion first expressed by him seven years 

 ago, that there really are shallow and deep-water species and genera, 

 though their bathymetric limits are not constant ; temperature much 

 more than depth is an important condition in molluscan life ; great differ- 

 ences in depth and temperature form the barriers of distinct geographical 

 provinces ; but there are species whose distribution is universal. Though he 

 does not desire to press negative evidence, Mr. Watson finds no trace, even 

 in the oldest and most widely distributed species, of essential lasting and 

 progressive change. 



In an appendix the Marquis de Folin describes the CoecidaB. 



' Challenger ' Marseniidae.f — Dr. E. Bergh takes the opportunity given 

 him by describing the few Marseniidse collected by the ' Challenger ' to 

 write a valuable and compendious essay on the structure and characters 

 of this family of Gastropods. A new genus, Marseniopsis, is described, 

 which forms a remarkable link between the diclinous and the androgynous 

 Marseniidse, and prevents our splitting up the family. M. pacifica from 

 Kerguelen and M. Murrayi from Marion Island, are the two new species of 

 this interesting genus. The only other example of the family found by the 

 ' Challenger ' was Marsenia duhia sp. n. 



' Challenger' Polyplacophora.t — The report by Prof. H. C. Haddon on 

 the few Chitons collected during the voyage of H.M.S. ' Challenger ' deals 



* Eeport of the Voyage of H.M.S. 'Challenger,' Mouograph xlii., 4to, London, 

 1886, 756 pp., 3 pis. 



t Report of the Vo3'age of H.M.S. 'Challenger,' Monograph xli., 4to, London, 1886, 

 24 pp. and 1 pi. 



J Eeport of the Voyage of H.M.S. 'Challenger,' Monograph xliii. (1886) 56 pp. 

 and 3 i>ls. 



Q 2 



