cephalopoda (decapoda), pteropoda. Moll. 65 
figs. 1-11. T. elongatus , Stp., n. sp., described and figured ; id. t. c. p. 189, 
pi. xxviii, fig. 13. 
Taonius sulimi ( Procalistes suhnii , Lankester) discussed and figured J 
id. t.c. p. 192, pi. xxxii, figs. 5-11. 
PTEROPODA. 
The memoir of Boas (2) is a valuable monograph of this group. The 
author considers that the Pteropoda are really Opisthobranchiata , and 
that the Thccosomata and Gymnosomata should be dissociated from 
each other and placed in this order as suborders or tribes ; for them the 
new names Eupteropoda and Pterota are proposed. No support is given’ 
to the alliance between Cephalopoda and Pteropoda maintained by various 
writers. Nervous system, Pelseneer, (5) cf. pp. 19 & 28, antea . 
GYMNOSOMATA. 
Boas (2) places these also noar the Tectibranchiata , but cannot decide 
their more precise affinities. He classifies them directly into the fol- 
lowing genera : — 
Pncumodermon (3 spp.), Spongobranchcea (1 sp.), Dexiobranchcca 
(4 spp.), Clione (1 sp.), Cliopsis (2 sp.), Halopsyclie (1 sp.), and Tlili- 
ptodon (1 sp.). 
Pelseneer (2) divides the Gymnosomata thus : — 
1. Pneumonodermatidce , containing Pneumonoderma , Dexiobranchcea , 
Spongio branchoea. 
2. Clionidce, containing Clione. 
3. Ilalopsychidai , containing Halopsyclie (= Eurybia). 
4. Notobranchceidce , containing : — 
Notobranchcea, n. g. : only one posterior branchia, composed of three 
crests (one dorsal, two lateral), the dorsal alone fringed. Posterior and 
anterior lobes of the foot long and narrow, the latter free in their 
posterior two thirds; for H. macdonaldi, n. sp., Atlantic. The genus also 
includes Clio capensis , Rang. 
Nervous system of most of these forms described ; id. (5). 
Cliopsis grandis , n. sp., Pacific Ocean, Boas, (2) p. 170. 
Dexiobranchcca (Boas, see Zool. Rec. xxii, Moll. p. G4), simplex , n. sp., 
Chili, id. t. c. p. 160. D. paucidens , Atlantic Ocean, id. t. c. p. 160. D. 
polycotyla , n. sp., Chili, id. t. c. p. 161. 
Halopsyclie , Bronn, takes precedence over Psyche and Euribia, Rang, 
and Theceurybia f Bronn ; id. t. c. p. 171. 
Pncumodermon macrocotylum , n. sp., Atlantic and Indian Oceans and 
China Sea ; id. t. c. p. 152. 
Thliptodon , n. g., for T. gcgenbauri r n. sp., a larval form described by 
Gegenbaur (Unters. ii. Pterop. u. Heterop., p. 95) ; id. t. c. p. 174. 
THECOSOMATA. 
Boas (2) regards these as nearly related to the Tectibranchiata , and 
especially to the Bullidce. No sufficient proof of their existence prior to 
