INVERTEBRATA, CRYPTOGAMIA, MICROSCOPY, ETC. 743 



margins of the mouth. Primary tentacles present or absent, vessels 

 communicating. The young forms are Cydippoid. 

 With oral lobes. 2. Lohake. 

 Body band-shaped. 3. Cestidoe. 



NUDA. 



No " grappling-lines." 

 Vessels ramify largely. 4. Beroidce. 



It will be seen that by this arrangement we get two distinct 

 groups, or subclasses ; the fom* sixborders have been long recognized, 

 but in addition to the presence or absence of the grappling-lines, 

 Chun points out that, as McCrady first saw for the Lobatce, both 

 these and the Cestidce have clearly diverged from the Cydipjndce more 

 lately than the Beroidce, inasmuch as they still retain in their life- 

 history an indication of their parentage. Leuckart recognized two 

 subdivisions equivalent to the Nuda and Tentaculata, which he 

 named respectively Eurystomata and Stenostomata ; it is now pointed 

 out that the diiference in the size of the mouth, or of the stomach, is 

 not a character on which any reliance can be placed. Taking then 

 the tentacles as his guide. Dr. Chun shows that where they have been 

 stated to be absent in any one of the Tentaculata, it is on account of 

 the insufficiency of the observations, or of some confusion of these 

 with other organs. The large mouth of the Beroidae, with their large 

 sabre-like cilia, the great development of the musculature and the 

 branching of the vessels, are points by which these forms make up for 

 the absence of the " grappling-lines," which are not present even in 

 the larval stages. 



The filaments are two in number in the Cydippidae, and are pro- 

 vided with a number of secondary lateral filaments ; in the Cestida) 

 and Lobatse they are present in greater nimabers, as simj)le filaments, 

 even where the larger tentacles are also present ; these simple fila- 

 ments are set in a groove, formed by a fold of the integument, which 

 extends from the base of the tentacles, along the margins of the 

 mouth, as far as the lobes. 



A further point, which appears to be of value in the classification 

 of the Ctenophora, is to be found in the arrangement of the water- 

 vascular system, which is in all cases really arranged along two 

 radii ; the variations in the arrangement are indicated in the foregoing 

 table. 



With regard to the systematic portion of the paper, of the Cydip- 

 pidse, four species of the Pleurobrachiadae, and four of the Mertensidae, 

 were found in the Gulf of Naples ; of these Fleurohrachia rhodopis, 

 Ewplolcamus staiionis, Lampetia pancerina, and Thoe paradoxa were 

 discovered by Chun. 



The author is of opinion that the five families formed by Agassiz 

 in the Lobatas cannot stand, as there are not presented any characters 

 which should be regarded as family ones; two new species are 

 described. 



With regard to the Cestidai the author points out in a note 

 that there is no Latin and no Greek word cesium, but that in both 



