Solenogaster Mollusks — SCHWABL 
265 
R 
FIG. 5. Prochaetoderma calif ornicum. Diagram of entire animal, showing arrangement of internal organs. 
b, Brain; bp, buccal plate; g, gill; gd, gonoduct; gpd, gonopericardial duct; gl, ganglion; h, heart; l, liver; m, 
mandible; oe, oesophagus; p, pericardium; ph, pharynx; r, radula; ra, radula cartilage; rc, rectum; rg, repro- 
ductive gland; s, stomach. 
GENUS Prochaetoderma Thiele, 1902 
Type P. raduliferum (Kowalevsky) 1901 
Prochaetoderma calif ornicum n. sp. 
Figs. 4-7 
COLLECTIONS: 
2228 (1) in 293 fm. 
2230 (3) in 300 fm, with Limifossor fratula 
and Crystallophrisson hartmani. 
2321 (34) in 385 fm, with C. hartmani and 
C. sp. 
2363 (2) in 429 fm, with C. marinellii and 
C. sp., juv. 
2411 (4) in 400 fm, with C. hartmani, C. 
hancocki, and fragments. 
2798 (5) in 386 fm, with C. hartmani and 
C. red sum. 
2802 (1) in 420 fm, with C. hartmani. 
2837 (2) in 454 fm, with C. hartmani. 
2839 (6) in 446 fm, with C. hartmani and 
C. hancocki. 
2899 (3) in 335 fm. 
3037 (1) in 360 fm. 
DIAGNOSIS: These very small animals meas- 
ure 2.25 to 3.05 mm in length; greatest diam- 
eter is 0.42-0.85 mm; they show a very char- 
acteristic habitus ( Fig. 4 ) ; a short head region 
is not separated from the following trunk re- 
gion ( Fig. 5 ) but is distinguished from it 
by the spines, which are small leaflike structures 
(Fig. 7), densely arranged and mostly standing 
upright on the body wall. The following region, 
occupying the greater part of the body and 
containing such main organs as stomach or 
mid-gut, liver, and gonads, is covered by flat 
imbricating spines arranged obliquely towards 
the dorsal midline of the body. The tail-like 
hind part of the body is provided with spicules 
resembling those of the head region but of 
larger size. The terminal end, containing part 
of the gonoducts, pericardium, and cloacal 
chamber with its organs, is protected by a 
