niAETODKinrv moxtereyexsis. 61 



somewhat though ganglion cells are lacking. From each of these enlargements 

 a nerve is developed, and after branching in tlie jiharyngeal musculature becomes 

 lost to view. This suhradular system does not appear with the diagrammatic 

 clearness of the one in ('. itlU intnUi, l)ut there is no esjiecial difiicuHy in determin- 

 ing its relations which arc essentially the same in the two species. 



In the posterior regions of the hrxly the nervous system very closely resembles 

 that of ('. attcnunta. 



The gonad, with the usual characteristics and relations, opens into the f(jr- 

 ward end of the pericardium by means of comparatively large tul)es in sexually 

 matui'e animals. In som(> animals, possibly owing to killing fluids, the peri- 

 cardial cavity is greatly distended with spermatozoa wliich have made their 

 way into the proximal half of the coelomoducts. These last named tubes com- 

 municate by wide openings with the pericardium and on the other hand extend 

 forward as ciliated tubes for a short distance. Bej'ond this point their walls 

 become glandular and are thrown into numerous convolutions which render it 

 impossible, without much effort, to determine their exact relations. Posteriorly 

 each duct becomes more simple, though of fairly large calibre, so that it con- 

 tracts the cavity of the cloacal chamber; and on the ventral border of the fold 

 thus developed the outlet canal is formed (Plate 29, fig. 5). 



Chaetoderma montereyensis, sp. nov. 



This species is evidently abundant in the deeper waters of Monterey Bay, 

 California, as 155 wei'e taken distributed through the following stations: nine 

 from 4485, seven from 4o()S, fifty nine from 4522, fifteen from 4523, thirty-one 

 from 4524 and thirty-foiu' from 4525. In every case the bottom was nuid and 

 the depth varied from 39 to 35G fathoms. C'hloretone (aceto-chloroform) was 

 used with good results as a narcotizing agent and 70 % alcohol served as a fixing 

 agent. The length of a medium sized specimen ' is 45 mm. with an average 

 diameter of 2 mm. through the prothorax and 3 nmi. through the preabdomen. 

 The color in life and ]ireserved material is yellowish white. 



The hypodermis \ery closely resembles that of C. atleiuiata. The spines 

 are represented in Plate 37, figs. 2, 3. 



The mouth opens through a slit in the subelliptical buccal plate (Plate 4, 

 fig. 17) and leads into a laterally comjiressed tube which becomes circular in 



' Generally speaking the larger siieciniens ooiiic from the shallower depths. Thi.s is very marked 

 in romparing those from Sta. 4.52,5 with others from Sta. 451)8. These size tlifferciices, however, do not 

 appear to be eorrelated with any constant st met ural peeuliarilies. 



