142 ALKXAXDllOMENIA VALIDA. 



elsewhere (hey are united by stronu; eonimissures. In the region of the shell 

 gland this organ is entered, and probably iiniervated, by several fibres which arise 

 from these ganglia. Poslerioi- to the last of the latero-pedal connectives three 

 or four small bi-anches pass into the muscles about the external reproductive 

 opening. No nerves have ever been followed from this source into the region 

 of the branchial huncllac, and if any are derived from this source they are of 

 V(>ry small size. 



Alexandromenia valida, sp. nov. 



Four specimens of this species (Plate 3, fig. 3) were collected off the coast 

 of southern California from the following Stations: 2980, 4382, 4389, 4391. 

 T\\v d('i)th langes from 603-1350 fms. and in every case the bottom was green 

 nuid. All the specimens were unattached so that nothing was learned of their 

 habits. The measui'ements of the largest specimen (Sta. 4389) are as follows: 

 length 32 mm., dorso-ventral diameter of head 3 mm., of cloaeal region 3 mm., 

 average diameter of l)ody 3..") nnn. 



The head is not distinct from the liody but is characterized by a more 

 pointed ajjpearance than the posterior end, and in all the specimens the borders 

 of the cloaeal opening are slightly expanded, exposing, to a slight extent, the 

 gill folds. The atrial opening is relatively small and its forward border is almost 

 level with the front end of the animal. A pedal furrow extends along the ventral 

 surface of the l)o(ly and posteriorly becomes continuous with the cloaeal cavity. 

 Anteriorly, for about 1 nnn. extent, it expands and allows the escape of the 

 anterior pedal gland seci'etion fPlate 21, figs. 2, 4) which, in the type, fills the 

 ojH'ning and extends posteriorly some distance along the ventral furrow. The 

 gen(>ral color of the Ixxly is light yellow. 



A well-dcveloiied dorsal sense organ is jiresent, situated in the type about 

 2 mm. from the posterior end of the animal. It is in the form of a shallow pit 

 and is especially conspicuous in surface view on account of the numerous hypo- 

 dermal jiapillae which surround it. 



The body is surrounded liy a cuticle, O.ii; mm. in thickness, which is crowded 

 with inmuncniblc si)icules and papillae of large size (Plate 33, fig. S). The 

 hypodermal layer is concei-ned almost wholly with the development of these 

 structuR's, the |)ortion i)rol)al)ly responsible for the formation of the cuticle 

 being limited to a fcnv cells packed between the bases of the papillae and develop- 

 ing spines. Everywhere the hypodermal elements are of small size, and though 

 excellently preserved are not favorable for study. 



As just noted the i)ai)illae are of enormous size and in a fully developed 



