270 CALIFORNIA ACADEMY OF SCIENCES. [Proc. 3D Ser. 



EXPLANATION OF PLATE XL 



Eudrilus Eugenics (Kinberg). 



Figs. 95-97. Sense-cells from the epidermis of the body-wall representing 

 types of the most common variations of those cells. Figs. 95 

 and 96 from transverse sections of the body, fig. 97 from longi- 

 tudinal section. In fig. 95 the narrow ventral protoplasmic dia- 

 phragm is contracted, in fig. 96 it is released. In figs. 95 and 96 

 this diaphragm points diagonally upwards to the right, but it often 

 points to the left. It is never horizontal, nor vertical. The num- 

 ber of marginal cells, in. c, forming the cap varies with the cell. 



Pontoscolex corethrurus (Fr. Muller), niexicanus subsp. nov. 



All the figures are drawn with Zeiss Apo., 2 mm., 1.40, Comp. Ocs. 4, 6 

 and 8, from preparations fixed in corrosive sublimate solution. Benda Iron- 

 haematoxylin, Eosin-thionin, or Eosin-toluidine were used in staining. 



Fig. 98. Auditory cell supported by two smaller surface cells, which sepa- 

 rate it from the cuticle. 



Fig. 99. Same. 



Fig. 100. Part of the auditory cell in which the archosome (spheres) has the 

 shape of a long sausage-like body. No star-shaped archosome 

 in this cell. 



Fig. loi, a and b. Two auditory cells. The archosomes differ greatly in size. 

 All structures except the archosomes are merely indicated. Oc. 4. 



Fig. ro2. Part of auditory cell. Two large archosomes, each with two cen- 

 trosomes. Oc. 8. 



Fig. 103. Part of auditory cell, only the archosomes are delineated in detail. 

 They differ greatly in size. Oc. 6. 



Fig. 104. Two archosomes from an auditory cell. Oc. 8. 



Fig. 105. Two archosomes from an auditory cell, one with two centrosomes, 

 the other with a somosphere and three centrosomes. 



Fig. 106. Two archosomes from an auditory cell. In one (a) there is a 

 star-like somosphere with centrosome, while b has a rounded 

 somosphere with at least two centrosomes. Oc. 4. 



Fig. 107. Two archosomes from an auditory cell. One (a) has two separate 

 somospheres, one with one centrosome, the other with two cen- 

 trosomes, connected by a narrow dark-staining band. Oc. 8. 



Fig. 108. Two centrosomes from different cells; one stained with Benda 

 iron-hsematoxylin, the other with eosin-thionin. Oc. 8. 



Fig. T09. Part of an auditory cell with two archosomes. 



Fig. no, a-k. Amoebocytes from coelom. Specimen from Tahiti. 



Fig. III. Microcytes from the coelomic fluid, same specimen as above. 



Dichogaster Crawi, sp. nov. 



Fig. 112. Lymphocytes from coelom. A and B typical forms, which con- 

 stitute the majority of cells; C, D, E, rare forms for comparison 

 of size with the other cells. A, B, C, Oc. 4; B, Oc. 6; E, 

 Oc. 8; Zeiss, Apo. 2 mm.; Eosin-Thionin, corrosive sublimate; 

 sections. 



Fig. 113. Cells from the prostomium, showing a bunch of common sense- 

 cells, also a single light-cell. Zeiss Apo., 2 mm., Oc. 6. 



Ocnerodrilus ( Nematogenia) lacuiim Beddard, panamaensis, var. nov. 



Fig. 114. A common mucocyte. 



Fig. 115. Several amoebocytes, cover glass preparation. 

 Fig. 116. Nematocytes; the cytoplasm consists of a single thread coiled like 

 rope. Zeiss 2 mm. , Apo. , Oc. 8. Sections in paraffin. 



Diplocardia Udei Eisen. 



Fig. 117. A, B, lymphocytes; C, microcytes. 



